Table of contents

Preface

The Institut Teknologi Bandung (ITB) will celebrate 100 years anniversary in 2019. One of the faculty, the Faculty of Earth Science and Technology (FEST) celebrated the 10th anniversary by November 2017. The Department Oceanography is within this Faculty. In accordance to government vision to put the nation "Toward Maritime Axis", we decided to take advantage of this momentum by organizing The 1^st Maritime Sciences and Advanced Technology (MSAT) conference on August 3-5, 2017 in Denpasar, Bali. This conference is one of the implementations of our Memorandum of Agreement between the Faculty of Earth Science and Technology - ITB, Geospatial Information Agency of Indonesia, and the Ocean College Zhejiang University.

About 70% of Indonesia is covered by ocean. Indonesian seas with complex coastline geometry, topography, and passages provide the only direct communication between the tropical Pacific and Indian Ocean known as Indonesian throughflow (ITF). Indonesia as one of the largest archipelago on Earth, plays a pivotal role in global ocean circulation and weather climate system. It hosts the strongest equatorial convective center that drives the global tropical atmospheric circulation. Along the route within the Southeast Asian seas, the water undergoes strong tidal mixing and air-sea interactions and other oceanic/atmospheric climatic processes associated with upwelling, Madden-Julian Oscillation (MJO), monsoon, El Nino Southern Oscillation (ENSO) and possibly the Indian Ocean Dipole (IOD). Hence, Indonesian seas are the center for Tuna fishing ground, world-most diverse marine biodiversity, and the same time prone to natural hazard associated with extreme climate events associated with ENSO and IOD. Fisheries and marine resources serve as main income generating sector for people in coastal areas. Because of strong tidal currents and many narrow passages with, many straits provide an ideal place for tidal current renewable energy. Therefore, our first MAST conference theme was "Ocean Science and Technology Toward a Global Maritime Axis" covered broad topics such as ocean-atmosphere dynamics, marine biogeochemistry, air-sea interactions, fisheries, food security, marine environment and pollution to marine technology and renewable energy. The Conference had been a good opportunity for participants coming from China (38 scientists), Japan (2 scientists), Australia (2 scientists), USA (2 scientist), Bangladesh (2 scientists), UK (1 scientist), India (1 scientist), Germany (1 scientists), Malaysia (1 scientist), Turkey (1 scientist) and Singapore (1 scientist) to present and discuss topics in their respective research areas.

The photographs from the conference can be found in the PDF.

All papers published in this volume of IOP Conference Series: Earth and Environmental Science have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Volume and heat transport variations through Karimata Strait during 2010-2014 were studied using three-dimensional numerical model of Hamburg Shelf Ocean Model (HAMSOM). Simulated area is located in 1°0'0" N - 4°30'0" N and 104°0'15"E - 110°30'0"E with a horizontal resolution 0.5' (approximately 0.94 km). The average of root mean square error of current velocity between model and observation are 0.17 for zonal (v) and 0.20 for meridional (v) components. The results of signal analysis showed that the volume and heat transport is strongly influenced by the seasonal period. There was also weak and medium phase of El Niño and La Niña during 2010 - 2014 that affected volume transport. The average volume (heat) transport during 2010-2014 through Karimata Strait is -2.75 Sv (-0.031 PW), meanwhile the average volume (heat) transport during boreal winter and boreal summer are -0.66 Sv (-0.06 PW) and -0.38 Sv (-0.03 PW), respectively (1 Sv = 10⁶ m³/s; 1 PW=10¹⁵ W). Southward total transport indicates that there are parts of South Chinese Sea-Indonesia seas flow through Karimata Strait.

An evaluation of a general circulation model from Massachusetts Institute of Technology (MITgcm) with Lat – Lon – Cap (LLC90) configuration was done. Simulation of 100 years yields the annual means of potential temperature, salinity, meridional overturning stream function and transport of several throughflows. A reference run with widened Davis strait from the model was used to compare with observational WOA09 data, and the MITgcm has reproduced reasonably reliable data. The patterns of potential temperature can resemble the WOA09, however not so for the salinity fields. An experiment to simulate the model in 5 different tuning set were then proceeded. For the potential temperature and salinity fields, the North Pacific and the Southern Ocean still has significant difference to the WOA09. The difference was in the range of -6 to 5 °C for the potential temperature and -0.5 to 3 psu for the salinity field. The meridional overturning circulation stream function was still lower than the observational (± 17 Sv); the MITgcm simulates it 10 ± 1Sv in the experiment. The root mean square (RMS) of the difference were calculated, the surface layer has the largest magnitude of difference due to the forcing dynamics. The best simulation, which has the least difference to WOA09, was the one with the original bathymetry and smallest vertical diffusivity coefficient, 1 x 10^-5 m² s^-1.

Mixed Layer Depth (MLD) is able to determine the amount of light and nutrients abundance for the growth of phytoplankton, its known that phytoplakton pigments are the main absorbers and light scatterers in the ocean. Location wich has deeper MLD and large seasonal variations are the most productive areas, also could have blooming or the maximum growth of large phytoplankton occurring in the existence of a limited number nutrients for several days. The aims of this study are to understand the characteristics of the MLD and it roles to the abundance of Chlorophyll and nutrient in Indonesia Through-Flow/ITF (Indonesia: "ARLINDO"), specifically the area along Makassar Strait. The Chlorophyll and oceanographic parameters were obtained based on measuring by CTD in TIMIT 2016 expedition. The MLD was deep (~43 m) in the northern part of the transect (around Central Sulawesi Island) and shoaled progressively until about 13 m in the southern transect (the Southern Makassar Strait). The Chlorophyll-a (Chl-a) concentration show a decline pattern from the north to the south transects with the maximal Chl-a is 0.37 mg/m³. Nutrient parameters in southern Makassar Strait studied were NODC (National Oceanographic Data Center) data from WOA (World Ocean Atlas), it can indicated a correlation between nutrient (Nitrate) with Chlorophyll. The mean correlation in mixing layer for whole area is 0.78, showing that Nitrate concentration is highly related proportional to Chlorophyll abundance, while below the mixing layer, correlation value is -0.52, indicating the inverse relation between Chlorophyll and nutrient. Based on those correlation, and assumption that the source of Chlorophyll is from phytoplankton, it can be concluded that phytoplankton needs Nitrate in its metabolism process as well as other productivities reason in mixing layer, while in depth below the mixing layer, growth of phytoplankton is no longer depends on concentration of Nitrate nutrient.

Indonesia is passed by an atmospheric phenomenon, called the Madden-Julian Oscillation (MJO), which has an impact on the wave height in the Indonesian Seas. The significant wave height is simulated using WAVEWATCH-III (WW3) numerical model in Indonesian region (90 °E-150 °E, 20 °N-20 °S) forced by surface winds from Cross-Calibrated Multi-Platform (CCMP), Navy Global Environmental Model (NAVGEM), and Navy Operational Global Atmospheric Prediction System (NOGAPS). This simulation is concentrated on MJO phase 3, 4, and 5 which passed through Indonesia and its adjacent waters that occurred in particular time between 1990-2015. In this study, the impact of MJO was analyzed during every monsoon season. In addition, wind speed analysis was carried out to further enrich the analysis of the MJO impact. The simulation result shows that MJO exerts the highest impact during phase 5 and DJF, which contributes to the increase of wind speed (WS) and significant wave height (SWH) in Indonesian inner seas by 6 m/s and 30 cm, respectively, and in southern Lesser Sunda Island by 8 m/s and 1.2 m, respectively. MJO can also contribute to decreasing of the WS and SWH, when it occurred during DJF and MAM phase 3, and JJA phase 4. There is no noticabe change of WS and SWH during SON.

This research showed the difference of thermocline layer depth during La Niña and El Niño events in the Makassar Strait, the main passage connecting the Pacific and Indian Oceans. La Niña event represented by 2011 and El Niño event represented by 2015. Three-dimensional numerical modeling using Regional Ocean Modeling System (ROMS) is used to determine ocean dynamic characteristics. The tides and atmospheric factor used as generating forces for coupled Ocean-Atmosphere-Wave-Sediment simulation model. Tidal elevation verification results from January to February 2017 showed a high confidence with RMSE = 0.148 m and MAPE = 13.51 %. Ocean circulation showed that water flows from north to south of the Makassar Strait in both conditions, El Niño and La Niña, indicating a transport from the Pacific to the Indian Oceans during those time. Two-dimensional seasonal sea surface temperature (SST) was used to determine the variability of thermocline layer depth. In general, based on simulation results, the depth of thermocline during La Niña was deeper than that during El Niño. The upper threshold of thermocline layer during El Niño phenomenon was shallower (average 27.29 m) compare to the threshold during La Niña (average 39.25 m). So do the lower threshold, during El Niño was shallower (average 160.47 m) compare to the threshold during La Niña (average 165.70 m). The thermocline thickness during El Niño (133.19 m) was found to be thicker compared to La Niña (126.43 m).

Balikpapan Bay is located in the East Borneo Province of Borneo, Indonesia and directly connected to the Makassar Strait and also has very important role in determining the dynamics of ocean current, heat and freshwater content in the Makassar Strait. Numerical model has been used to simulate the dynamic process such as the changes of water mass in the Balikpapan Bay. We have used the terrain following three-dimensional Regional Ocean Modeling System (ROMS). Tides, river discharges, and atmospheric forcing (surface fields) have been used as generating forces for the model. The model has been simulated for three months from 1 October 2012 to 1 January 2013. The model has been validated by computing the RMSE, MAPE and Willmott's index of agreement (d) using water level observation at the sampling station in Semayang port, Balikpapan. The verification showed a good agreement between model prediction and field observation data with RMSE = 7.8 cm, MAPE = 14.3% and d = 0.995 (with a value of perfect agreement equals to 1.0). The results analysed using vertical profile of salinity and temperature from 22 sampling stations with 11 stations located at the inner part of Balikpapan Bay. While the other stations located outside the Balikpapan Bay were used to analyse watermass. Water circulation is mostly dominated by the forcing from tides. The model results showed that the outer part of Balikpapan Bay is saltier than the inner part of Balikpapan bay. The highest average temperature occurred along coastal areas with value ~31 °C. The distribution of vertical salt transport showed that the water masses tend to be stratified during neap tides and mixed during spring tides condition.

This study aimed to investigate the effects of currents to wave height in the waters of Merak Port, Banten using wave spectrum model. The wave-current interaction simulation was performed by utilizing SWAN (Simulating Waves Nearshore) in stationary mode and using the unstructured triangular grid. Data of wind velocity and direction as model inputs were obtained from BMKG (Indonesian Agency for Meteorology, Climatology, and Geophysics), whereas tidal current velocity data was obtained from TMD (Tide Model Driver). The model was simulated in two different scenarios, i.e. without and with following (adverse) current which is same (opposite) with wave propagation. The model input of dominant west wind was used to represent the west monsoon, while the dominant wind from the north was used to represent the east monsoon. The simulation results show that the maximum wave height is 2.98 m in the west monsoon and 1.9 m in east monsoon. In the west (east) monsoon the following current decrease wave height to 9.26% (5.09%), while the adverse current increase wave height up to 9.07% (6.56%).

Major national and international ship traffic routes pass through the western part of Java Sea. Due to this reason, this area is vulnerable to oil spills from ships and offshore exploration. One of the most vulnerable areas to oil pollutant is the MPA (Marine Protected Area) of the Seribu Islands, particularly the region around Pari Island. The current study was part of IndoNACE (Indonesian seas Numerical Assessment of the Coastal Environment) project and aimed to assess the coastal vulnerability towards oil spill using a Geographic Information System (GIS). In this frame, a spatial analysis was conducted by overlaying coastline map, bathymetry map, and ecosystem distribution map. The overlay method was referred to the Environmental Sensitivity Index Guidelines created by NOAA (National Oceanic and Atmospheric Administration). The preliminary results showed that 38%, 24%, and 38% of Pari Island coastline were high, moderate, and low vulnerable towards oil spill pollution, respectively. The low and moderate vulnerable areas were located at the outer reef crest and inner lagoon. Meanwhile, the high vulnerable area was located at the vegetated shoreline which dominated by mangrove. Due to its biological value and its role in the environment, the vegetated area should receive priority protection against oil pollution.

Segmentation is the process of dividing and grouping the pixel of an image into a segments or objects with the similar characteristics into homogenous areas. This method is expected to get better result with relatively faster result compared to manual (digitation) method. Side-scan Sonar image segmentation using Multi-resolution segmentation algorithm with considered many parameter and using pixel based threshold. The segment grouping using spectral reference by emphasizing the degree of brightness and texture where the two parameters are related to each. Segmentation with two parameters (brightness and texture) is effectively used for targets located near a towfish because of higher target spectral heterogeneity. TVG (Time Varried Gain) correction deliver more detailed result, image with TVG have highest accuracy of 0.987. This proves that the TVG correction that regulates the backscatter to affect the hue in the image has an important role in the seafloor classification process, in addition it can sharpen the appearance of the target which is far from the tow-fish range. Weakness of energy during measurement caused by angle and distance from instrument to target far from the towfish will affect the value of brightness and texture.

The spatial and temporal of Temperature and Salinity in the Eastern Indian Ocean (EIO) are studied by using Argos data. EIO consisting of Pacific seawater mass which passing through Indonesian seas and mix with Indian Ocean itself that form complex formation. It reveals link among ITF, SEC, Leeuwin Current, and SJC and routes into global circulation. The purpose of this study is to describe the main physical properties variability based on Argo Floats data. The dataset is used from 80 Argo Floats during 1999-2016 within area south of Java to west of Australia with depth range 0-2000 meters. The result shows that vertical temperature and salinity profile quite homogeny near Sunda Island-West Australia. Monthly spatial distribution of temperature is founded 15-30° C, and varying in lesser Sunda. Vertical profile in 4 sections is shallow at near Java, but shows differences in 25 horizontal. Salinity profile is having range 25-34 psu. ITF is contributing to EIO mixing. Finally, salinity is a parameter that affects the EIO dynamics especially in near Australia basin. The SEC variability showed clear in between 10°S to 15°S.

Wave propagation is an interesting subject to be modelled and studied in oceanography. Interfacial wave is one of waves that can occur between two fluid-layers of different density. Since the complexity of the problem, simplification is made by considering a specific type of wave, i.e. monochromatic. In propagating, the transmission and reflection of the wave are considered as the effect of disturbing of the fluid depth. It can be made by putting a bar on the bottom of the channel. The dimension of the bar plays an important role in obtaining the minimum amplitude of the transmitted wave. This is then continued to determine the distance between two bars to get the minimum amplitude. The result was presented in the MSA-conference.

The Boussinesq-type of equation is considered here as a model for describing interfacial wave dynamics in a two-layer fluid system. The equation, which is derived under rigid-lid assumption, has first order nonlinear term and dispersion term, and it holds for interfacial wave with long wavelength and small amplitude, relative to depth. The second-order Mac-Cormack scheme is implemented to solve this Boussinesq model. The numerical scheme is validated by simulating solitary wave as well as monotonic bore. Finally, the evolution of solitary wave propagating over a variable bathymetry with a shelf is examined.

Storm tide is one of the major natural hazard that can be endangered property and residents around the coastal region. A storm tide flooding has been occurred in Kupang, East Nusa Tenggara (NTT) on April 28^th 2017 during the appearance of Tropical Cyclone Frances. The aim of this paper is to evaluate the coastal flooding events due to cyclone in order to develop the mitigation strategies in case of similar events in the future. The data from cyclone, such as the track and phase, were shown to see the cyclone stage and its impact to the changes of the waters on the coast of NTT. Three-hourly numerical hindcast of significant wave height (H_s) and primary swell from Indonesian Agency for Meteorology Climatology and Geophysics (BMKG) were used to analyze the waters condition of NTT area. The hindcast was modelled using GrADS with a resolution of 0.125° x 0.125° which has been operationalized by BMKG. Meanwhile, the sea level anomaly from AVISO Satellite Altimetry Data was used to examine the variation of regional sea level variation during the flooding occurrence. From the processing of several data and the analysis, we get that the significant wave and the swell have reaches 6 m high in on the peak of the cyclone event with the sea level anomaly is 10 – 15 cm. Thus, we conclude that this event was occurring because of the swell assisted with the strong steady wind, where the energy could transported the waters up into the mainland.

This study aims to investigate the characteristics of diabatic heating profiles associated with appearances of Mesoscale Convective Systems (MCSs) over Sumatra Island (SI) and Indian Ocean (IO) including the transitional offshore zone (TZ). We define the parameters of eccentricity, cloud lifetime, and cloud coverage from Multi-Functional Transport Satellite (MTSAT) infrared imageries to identify the MCSs. We derive the diabatic heating profiles over SI and IO using radiosonde data collected during Cooperative Indian Ocean Experiment on Intraseasonal Variability in the Year 2011 (CINDY2011) / Dynamics of the Madden Julian Oscillation (DYNAMO) campaign. We also estimate the diabatic heating profiles from the GPS Radio Occultation incorporated with the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data over TZ, where the radiosonde observations were limited. The results show that heating occurred throughout the entire troposphere during the mature stages of MCSs with more variations in the amplitude and maximum heating up to 20 K/day overland. Furthermore, the altitude of maximum heating over SI is lower than that of IO and TZ. Over SI and TZ, profiles of dissipations (postmature) stage are characterized by cooling in the lower altitude and an upward shift of maximum heating. By analyzing vertical velocity profiles, we confirm that cooling (heating) processes are associated with updraft (downdraft) in the cloud systems. In addition, the presence of cooling that occurs in layers close to the surface could indicate the formation of cold pool during the dissipation phase of the MCSs.

Semiannual current variation in the equatorial Indian Ocean is examined using currents velocity records from Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) Program. Spectral analysis shows that semiannual variation is the strongest variation in equatorial Indian Ocean. Further analysis exhibits that this variation is associated with Wyrtki Jet phenomenon and forced by wind along the equator. Upward phase propagation (downward energy propagation) is clearly shown as indication of the propagation of equatorial Kelvin wave. Cross correlation of two mooring data captures westward propagation of reflected Rossby wave that interferes the propagation of Kelvin wave. During IOD positive event, stronger reflected Rossby wave occurs and causes weakening of upward phase propagation. This result reveals that interferences of equatorial wave have important role on forming vertical structure of currents along equatorial Indian Ocean.

Interannual variability of sea surface height (SSH) in western Pacific Ocean and eastern Indian Ocean occurs as a result of the ENSO phenomena. This variability affects SSH difference between both of those oceans. In normal condition, SSH in western Pacific Ocean is higher than in eastern Indian Ocean which causes a current that passes through Indonesia which known as the Indonesian Throughflow (ITF). This study used SSH and geostrophic currents data from 1993 to 2015 which obtained from AVISO satellite altimetry data to determine the variability of SSH difference in ENSO condition which represented by the sea surface temperature (SST) anomaly of Niño 3.4 data from NOAA and its relation to the geostrophic currents in Lombok Strait which is one of the ITF crossing path. The result of the correlation calculation of ENSO condition to SSH difference between western Pacific Ocean and eastern Indian Ocean shows the negative value. It means that SSH difference at both oceans have opposite condition that when El Nino happened SSH in western Pacific Ocean is lower than the eastern Indian Ocean and when La Niña happened SSH in the western Pacific Ocean is higher than the eastern Indian Ocean. The SSH difference does not affect the direction of geostrophic currents but affects its speed.

Water temperature variation and its correlation to meteorological factors and climate variation was studied at Segara Anakan Lagoon of Sempu Island during January 2012 to December 2013. Tidbit water temperature data, ECMWF meteorological data, climatic indices were analysed statistically. The result showed that the range of water temperature was between 23.7 to 30.4°C. Pearson correlation between water temperature and meteorological factors varied seasonally. The highest water temperature (30.4°C) occurred in Northwest Monsoon, was mainly affected by precipitation (r = -0.999). While, the lowest ones (23.7°C) in Southeast Monsoon, was affected by all meteorological factors. Furthermore, in transitional seasons (transitional-1: r = 0.977; transitional-2: r = 0.744), it was affected by solar radiation. This study also informed that there was no difference between water temperature and satellite SST (t<t_tab: 1.288<2.074; sig: 0.211>0.05) which showed that satellite SST were able to substitute the limited in situ data (Tidbit water temperature). PCA analysis indicated that climate factors (mainly SOI and DMI) affected water temperature of Segara Anakan. Present study suggested that good quality with direct and continuous measurement of local water temperature data and compiled with meteorological data and climate index were important for further prediction of water temperature variation as climate adaptation in South Malang.

Semarang is one of the coastal areas in Indonesia that frequently occur tidal flood. Tidal flood is a phenomenon where the sea water entering the land area. It can be influenced by astronomical factor that is gravity of moon and sun besides meteorological factor which also play a role in rising the sea level. Sea level rise can cause flood disaster in coastal areas if the height of coastal land is below sea level. At the time of minimum sea wave height, sea level rise is also low, so rising sea level is only played by high tidal fluctuations. Wind data used in this study. The data classified into land breeze, sea breeze and wind transition. From wind data, three classifications of wind speed are determined that is when the wind with minimum, average and maximum speeds. The method of calculating some variables of sea level rise (wave set up) as well as sea tidal observation and measurement. From this research it can be seen that sea level rise in Semarang besides caused by tidal factor is also caused by meteorological factors such as wind speed.

Tsunami risk is defined as mathematical product between vulnerability and hazard. Tsunami risk also refers to the estimated loss from a given hazard to a given element at risk, and it is defined as a combination of tsunami hazard, tsunami vulnerability, exposure, and event probability. Besides tsunami vulnerability, tsunami risk is assessed by a number of criteria. This study applies the combination of element at risk to assess tsunami risk area along coastal area of East Java Indonesia. The study introduces the spatial multi-criteria analysis into tsunami risk assessment along with the existing perspective evolving the role of GIS. In this study, the existing vulnerability parameter was analysed and evaluated. The analysis was done using GIS-based spatial multi criteria approach. All parameter were analysed through weighted overlay using analytical hierarchy process and geospatial analysis. The results are provided as thematic maps of tsunami vulnerability map and tsunami risk map. Tsunami risk maps as a result from this study illustrate five levels of risk from very low to very high based on geospatial analysis. It describes that coastal area with low elevation was at high risk to tsunami, similar to that indicated in tsunami vulnerability map. Coastal area with high density of vegetation describes a low level tsunami risk. The existence of river and other water stream along coastal area are also important parameters in generating tsunami risk map. Risk map highlights the coastal areas with a strong need for evacuation capacities, including evacuation route and evacuation building.

National Capital Integrated Coastal Development Program (here in after called NCICD Program) in Jakarta as National Capital City has main function for flood protection and to countermeasure the land subsidence purposes. According to Bappenas (National Planning Agency), the Updated-Masterplan NCICD program has three phases; 1) Critical-phase 2) Mid-term phase 3) Option-phase. The critical-phase sea dike construction is projected to protect Jakarta until 2030. Land subsidence is the main factor that the critical-phase of sea dike must be constructed. Jakarta sinks down with the range of 2-20 cm/year. Therefore, the existing dike level also becomes lower along the time. Three focus area of sea dike construction under Ministry of Public Works and Housing (here in after called PUPR) are Muara Kamal, Kalibaru, and Muara Baru. At the moment, PUPR concentrates in Kalibaru and Muara Baru with the physical construction progress around 48% from the total length 4-8 km and it will be finished in 2019. These are essential due to many people live there. The construction of typical sea dike is spoon-pile with shifting construction to the sea between 50 m-100 m from mainland with the crest level +4.8 m from Lowest Water Spring. This type is chosen due to its efficiency on spatial and preventing social conflicts. In addition, the space between the main land and the spoon pile will be nourished by the sand to use it for public infrastructure, such as park. The material behind the dike and the toe protection in front the dike is used for stability purposes, avoid scouring, and reducing wave energy interact the dike itself.

Benoa Bay is estuary of six rivers in Bali. In addition to carrying water, river flows also carry nutrients (nitrate and phosphate) derived from activities along the watershed. High nutrient concentrations have potential for eutrophication that leads to the Harm Alga Booms. The aims of this study were to determine the concentration, load, and tropic level of nutrients (nitrate and phosphate) in river which ends at Benoa Bay. Measurement of nutrients in water used brucine method for nitrates and ascorbic acid method for phosphate. The results were then compared with ministerial decree of the environment No 51 in 2004 for marine biota. The result show concentration of nitrate and phosphate is fluctuated along years. Nitrate concentration fluctuated form undetected to 16.950 mg/l, meanwhile phosphate concentration from undetected to 3.275 mg/l. The highest concentration of nitrate and phosphate found in dry season and the lowest concentration found in wet season. Nitrate and phosphate load to benoa bay also fluctuated in each season and river. The highest nitrate load found in Mati River during second transition season (4.387 tons/day) and also in Buaji River during dry season (4.366 tons/day). The highest phosphate load to Benoa Bay also comes from Mati River in dry season (6.980 tons/day). The Eutrophic condition for nitrate generally found in Second Transition Season, meanwhile for phosphate generally found in all river and season. The concentration of nitrate and phosphate found in all rivers and season which ends at Benoa Bay generally exceeded the quality standard base on Ministerial decree of environment No 51 in 2004 for marine biota. These conditions are potential for trigger eutrophication process in Benoa Bay.

Decapterus sp. is one of the main targeted species for small pelagic fish in Java and western Kalimantan Seas (Karimata Strait and South China Sea). Decapterus sp. mainly catch at around 40-70 meters depth. They live in warm waters (more than 26°C) with salinity greater than 30 ppt, pH greater than 7.75, and concentration of dissolved oxygen (DO) greater than 4.2 ml/l. Datas were obtained from World Ocean Atlas 2013, NCEP, and result of numerical model. The aim of the research was to investigate the seasonal variation of decapterus sp. potential fishing ground. The results show that variation of seasonal oceanographic conditions has an impact to the potential fishing ground pattern of decapterus sp. The catching prediction area was at 20 m depth, except when second transition season which was at 40 meters depth. Fishing period should be done during the rainy season according to the widest area of potential fishing ground.

The accumulation of plastic debris in the oceans has been widely recognized as a threat to marine environment. A recent study estimated that Indonesia is one of the biggest sources of plastic wastes in the ocean, but directly-measured abundance data from the seawater in Indonesia is lacking. We documented the abundance and distribution of microplastics (size <5mm) in sub-surface seawaters of Sumba, a pristine region in Indonesia. Water samples were collected from 5 m, 50 m, 100 m, 300 m depth and near the sea bottom. Samples were examined for microplastics using flotation and filtration methods. We found microplastic in all sampling locations, consisting of fibers (45.45%), granules (36.36%) and other plastic form (18.18%). Most of microplastic particles were found at water depths less than 100 m (81.82%), which was the thermocline area. Our finding corroborates the believe that plastics has widely invaded marine environment in different parts of the seas and oceans, including pristine, remote, and unknown areas.

Understanding and predicting the acoustic backscattering from seafloor substrates was essential to support the management and development of coastal area as well as offshore. The aims of this study were to quantify the acoustic backscattering strength from the seafloor substrates, classify the types of seafloor substrates, as well as correlation between the seafloor substrates and the value of surface backscattering strength (SS). The data collection was done in April to June 2016 in the Indian Ocean WPP 572-573 using hydroacoustic instrument SIMRAD EK60 with operating frequency of 38 kHz. Substrate sampling was used for data validation using Van Veen Grab. The results showed that the SS value for the type of sand substrate (-8.05 dB to -5.25 dB), silty sand (-8.15 dB to -7.03 dB), sandy silt (-11.30 dB to -11.35 dB), silt clayey (-14.71 dB to -12.17 dB) and clay substrate -23.55 dB. Between the SS value and the sand percentage had a very strong positive correlation, and a very strong negative correlation between the surface backscattering strength and the clay percentage. In contrast, a poor negative correlation was also found between the SS value and the silt percentage.

A determination of the primary productivity in coastal ecosystems, namely mangrove, seagrass and coral reef was done in the Seribu Islands (Kelapa Dua Island, Pramuka Island and Pari Island). Data collection was performed by oxygen methods with a light-dark bottle. Data were collected on 11 - 16 February 2016. The data were Mangrove density, seagrass density, seagrass cover, and, coral reefs cover. Physical-chemical parameters of the water were water temperature, salinity, dissolved oxygen, and nutrient content. Mangrove density in Pramuka Island is the highest among the others with density 19,500 trees/ha. The highest seagrass density is found in Kelapa Dua Island of 1,099 stand/m². Life corals in Kelapa Dua Island has the highest coverage by percentage of 53.2 %. The calculation results of primary productivity values show the highest value in Pulau Kelapa Dua up to 3.0062 gC / m² / day. The lowest value obtained in Pari Island that was equal to 0.6 gC / m² / day. Based on research, mangrove density, seagrass density and life corals coverage have a positive correlation to primary productivity.

Karangsong beach is located in the north of Indramayu district at Karangsong village. It has an area of approximately 25 Ha for mangrove forests conservation. This research had been conducted from April to June 2017 with a purpose of surveying mangrove's diversity and density, evaluating the status of mangrove ecosystems, and assessing the management of mangrove marine tourism area in Karangsong, Indramayu. We found out that throughout the whole ecotourism area, there are three types of mangrove: Rhizophora mucronata, Rhizophora apiculata and Aviciena marina. The biophysical status of mangrove ecosystem proves to be suitable for ecotourism, operations are well managed and could be accounted for its sustainability.

Whiteleg shrimp (Litopenaeus vannmaei) commodities has a high economic value and a huge market demand. Changes in temperature and precipitation seems to be the most significant factors climatic that effect shrimp aquaculture production. The objectives are to understand of climatic factors influence on the whiteleg shrimp farming sector in Indonesia based on IPSL(Institut Pierre Simon Laplace)-CM5A-MR(Medium Resolution) model and to understand adaptability of whiteleg shrimp to climate change on vulnerable area. The projection of the model includes four Representative Concentration Pathway (RCP) scenarios, encompassing RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5. These vulnerable map were created by overlaying the exposure maps (precipitation, maximum temperature and minimum temperature) and sensitivity map (production maps) in various time. Banyuwangi District was the most vulnerable area in East Java Province. The questionary has analysed descriptively and found that 92% of the respondents are aware of climate change. The respondents reveal that increased on rainfall (34%) and decreased of temperature (29%) has negative impacts on shrimp production. Decrease in production influenced by disease and climate factors. Either future threats or current threats related to climate change and disease. More deeply there are insignificant positive correlation between temperature and precipitation with production in Banyuwangi.

Indonesia is the largest archipelagic country in the world, with two third of waters containing large marine resources. However, the coastal and marine resources have not been optimally utilized due to the limitation of Spatial Zoning Plan for Coastal and Small Islands (RZWP3K). In addition, there were many institutions which produce thematic maps of the coastal and marine resources (MGI) using different basemap, standard and technical specifications. Hence, same thematic maps provide different information. For these reasons, One Map Policy (OMP) is required to overcome the problems. The objective of this research was to develop datasets of one map of the coastal and marine resources needed for developing RZWP3K by using thematic layer maps produced by their respected Ministries/Agencies as the custodianships. The current custodianships of thematic maps in Indonesia is defined based on the Head of Geospatial Information Agency Decision Number 54 Year 2015. The method used the OMP approach was based on one reference, one standard, one database, and one geoportal. The research resulted the dataset of MGI integrated to the national basemap in a geodatabase format. From this research, it was concluded that the thematic maps of the coastal and marine resources which were produced in many institutions can be integrated to a national basemap and standard specification. The integrated thematic maps are then useful for developing the RZWP3K.

The Santolo beach is one of the tourism beaches in Regency of Garut, West Java, Indonesia. The position of Santolo beach which facing towards the Indian Ocean, caused limited water activities that makes beautiful scenery is the main attraction for tourists. This research aims to determine the value of aesthetic quality Santolo beach scenery based on the viewshed. Three analysis approaches are used to solve the research problem, that are the Kernel Density, the Viewshed Analysis and the Euclidean Classification. The results show there are 5 viewshed areas with an average area of 0.14 km². Each viewshed has a varied aesthetic quality value between moderate to good. In generally the Santolo Beach can be developed become the coastal tourism.

Escherichia coli and Aeromonas hydrophylla are well known pathogenic bacteria causing diseases in both human and animals. Since the popular antibacterial drugs in the market lead to resistance, other alternatives antibacterial need to be searched from the active ingredient found in marine and terrestrial vegetation. The potential use of secondary metabolites from marine vegetation is currently being developed. One of marine vegetation that has been expected to have antibacterial activity is mangrove. This study aims to provide information related to the phytochemical and antibacterial activity of methanol extract of the bark of mangrove Rhizophora mucronata. The phytochemical screening and disc testing methods were used in this study. The results showed that the methanol extract of R. mucronata containedphenolics, alkaloids, and terpenoids. Furthermore, the positive outcome of active antibacterial potential of the methanol extract against E. coli and A. hydrophilla has been indicated by inhibition of discs in a clear zone at 7,56 and 7,00 mm.

A study aimed at investigating the effects of four different materials ropes as substrates for settling and metamorphosis of tropical oyster, Pinctada maxima, pediveligers was conducted at laboratory scale. The number of pediveligers attached and metamorphosed on each substratum were counted at the termination of the experiment. Increment in shell length during settling and metamorphosis was also measured. Settling and metamorphosis were analyzed using One-Way ANOVA with substratum as the main effect. Two-Way ANOVA with time and substratum as the main effect on growth was also tested. The results showed that the settling and metamorphosis of pediveliger were affected by the substratum. The number of settled and metamorphosed pediveligers on polypropylene rope, natural ropes of Arenga piñata and Cocos nucifera was significantly higher than on the bottom of Pyrex glasses. No significant difference between numbers of larvae settled on polypropylene and natural ropes of Arenga piñata and Cocos nucifera appeared. A significant effect of time, but not of substratum, on growth occurred. Overall, settling and metamorphosis of P. maxima pediveliger larvae were strongly affected by artificial and natural ropes, while metamorphosis occurred haphazardly on the Pyrex glass. Growth occurred after settling and metamorphosis.

The assessment of ecological resilience is a new approach to support coral reef management, especially in addressing anthropogenic stresses and anticipating the impacts of climate change. This study applies advanced scientific approaches to spatially assess the relative resilience potential and to determine management actions on coral reef ecosystems in Doreri Bay, Manokwari Regency, Indonesia. The combination of underwater photo transect (UPT) method, belt transect, Aqua MODIS satellite data processing, interview, observation and laboratory analysis were applied to collect 11 resilience indicators data, consist of 7 process indicators and 4 stress/pressure indicators. The relative resilience potential and stress were analyzed through several stages including data compilation, normalization, scale setting, and calculation of resilience and stress value, site ranking and site categorization. Furthermore, the relative resilience potential, relative stress values, and the value of individual indicators were queried using criteria to determine target sites and appropriate management actions. The results indicate a spatial variation of the relative resilience potential of coral reefs, where sites with high resilience potential values are located near local community settlements, particularly around Lemon Island and Mansinam Island. Efforts to reduce pollutant sources from land are necessary on sites located near river estuaries and densely populated settlements. Most of the sites meet the criteria for fisheries management/enforcement. Efforts to manage fisheries and law enforcement need to be done on sites at the reefs of Sawaibu and around Raimuti Island.

This paper presents new finding from the sedimentary sequences, overlooked by previous researchers, which provide insights to the sea level changes during the deposition of the Middle to Late Pliocene Kalibiuk Formation. Data were acquired from fieldwork via detailed measured section of each sedimentary sequence from the bottom to the upper part of the formation followed by molluscan fossil association analyses. Lithologically, the Cisaat River stratigraphic section is dominated by greenish grey claystone with some light grey fine-grained sandstone intercalation. Based on about 50 m stratigraphic section, 10 molluscan fossils associations were successfully determined. The sequence from bottom to top are: Corbula – Natica association, Nassa sp. association, Olividae – Turricula association, Pecten – Telina association, Telina – Placuna association, Corbula – Marginella association, Placuna – Natica association, Turritella association, Turritella – Marginella association and Dentalina – Architectonica association. Changes in vertical succession of the molluscan association indicates a development from shallow marine to terrestrial depositional environment before gradually overlain by terrestrial sediments of the Kaliglagah Formation. At least there are 2 deepening - shallowing sea level cycles during the deposition of Kalibiuk Formation observed from this section.

Ichnofossils content of Paleocene source rock sediment were examined based on two wells cores from Bintuni Basin, West Papua, Indonesia. The cores are from Paleocene interval of Waripi - Daram Formations and known as the potential source rock sediment interval. This study aims to determine the sea level changes during the depositional of the Waripi - Daram Formations. Representative of 18 ichnogeneras including: Arenicolites, Asterosoma, Chondrites, cryptic bioturbation, Glossifungites, Helminthoida, Nereites, Ophiomorpha rudis, Palaeophycus, Phycosiphon, Planolites, Rosselia, Scolicia, Skolithos, Spirophyton, Teichicnus, Thalassinoides, and Zoophycos. The sea level curve generated from both wells based on ichnofossils association, suggest that there were at least three deepening – shallowing cycles. The cycles generally begins by inner to middle neritic interval that sign by appearance of Ophiomorpha and Chondrites with few Phycosiphon, while the deeper interval of outer neritic, upper bathyal into abyssal usually indicated by Zoophycos, Helminthoida, Nereites, Spirophyton and abundant of Phycosiphon. Sea level curve reconstructions based on the depositional environment suggest that during Paleocene Well-2 was located closer to the land compared to Well-1. Rapid shift in the depositional environment could indicate an initiation of regional uplift in the area caused by a new subduction system to the north of the Basin.

Tropical cyclone is an atmospheric phenomenon formed above warm ocean in a tropical region. Generally, tropical cyclone gives negative impact, such as extreme rainfall, strong winds, and extreme wave height. On the other hand, however, tropical cyclone gives positive impact on triggering the ocean fertility by induced chlorophyll-a concentration caused by vertical mixing and upwelling in the ocean. Related to this, a study has been conducted to determine the concentration of chlorophyll-a after the occurrence of Ernie cyclone in Indian ocean near western part of Australia and along the southern coast of Java island. The data that used in this study is daily wind speed data from 5 - 11 April 2017, daily average data of SST from 5 - 11 April 2017, and 8-day composite data of chlorophyll-a data from Aqua-MODIS satellite. The analysis of chlorophyll-a concentration showed a slow response of ocean fertility increment in the southern coast of Java island. Chlorophyll-a concentration along the cylone trajectory prior to the cyclone was in the range of 0.08 mg/m³ – 0.15 mg/m³ and significantly increased up to 88%–100% in a week after the occurrence of cyclone. On the next third and fourth weeks after cyclone, the concentration of chlorophyll-a along the cyclone trajectory decreases gradually. Meanwhile its sea surface temperature decreased significantly, especially in areas where cyclone had passed.

Bulang Kebam Island is one of the small islands located in the west part of Batam City, Riau Islands Province. The region has a deficiency of energy because both central and local governments have not been able to build electrical grid connections for the region, hence the electricity demand can only be met for six hours per day using a diesel generator. In order to provide a more continuous supply, an alternative source of energy by utilizing the potential of tidal energy resources around Bulang Kebam Island is needed. In support of an effective and efficient renewable energy project development, a study of the community readiness level in Bulang Kebam Island is conducted. Rapid Appraisal for Community Readiness (RAPCR) method is used for this purpose, which consists of social, economic, environment, technology, and institutional factors. The results showed that the community readiness index were categorized as sufficiently ready with values of 61.84, 64.15 and 72.55 for the environment, technology, and institutional factors respectively. While from the economic and social factors, community readiness index were categorized as ready with values of 82.94 and 84.93. Furthermore, the dominant attributes from each factor were analyzed and ranked by using Leverage analysis. The most dominant attribute from economic, environment, technology, social, and institutional factors respectively are potential for renewable energy funding from the community, level of environmental difficulty on the implementation of renewable energy, area availability for renewable energy technology, a clear roles in the implementation of renewable energy, and commitment of local government to renewable energy. The results of this study is expected to be a reference and recommendations for the development of appropriate target and advantage of renewable energy project development in Bulang Kebam Island.

Ocean thermal is one of the renewable energy resources. In 1981, a design of Ocean Thermal Energy Conversion (OTEC) pilot power plant was proven could produce electricity. The performance of OTEC depends on the possible temperature differences of the warm and cold seawater, at least 20°C. In the coastal of Para'baya, this requirement can be satisfied since the distance to reach the 1000 m depth is less than 10,000 m from the shore. The result of ocean thermal power calculation in Makassar Strait shows that Para'baya could produce higher power than any other place in west coast of Sulawesi, with an average power output of 120.35 kW. This ocean thermal study, in the coast of Para'baya, used sea surface temperatures (SST) data from the result of Long-term Indonesian Throughflow Model Simulation (LITHMOS) over 24 years (1982 – 2006), and sea temperature data at 1000 m depth from the World Ocean Atlas (WOA) 2009. The result shows that ocean thermal energy distributions in the Makassar Strait were affected by the combination of gust, wind direction, and sun position which varies in each season. Maximum ocean thermal power is reached during the first transitional season (March, April, May) with output power of 128 kW, and the minimum power is achieved during the dry season (June, July, August) with an output power of 114 kW.

Nowadays satellite altimetry has become an advanced instrument to observe many natural physical phenomena, such as sea-level rise, ocean circulation, water mass changes, and marine gravity anomaly. The use of satellite altimetry data to compute marine gravity anomaly provides good results and costs relatively low. Those advantages make geodesists utilize this method as an alternative in geoid determination, especially over the seas. Several sets of satellite altimetry data from Cryosat 2, Jason 1 phase C, Geosat and ERS1 were used to compute gravity anomaly over the surrounding waters of Kalimantan and Sulawesi Island in Indonesia. The study area spans between -7°-7° N and 108°-127° E with a spatial resolution of 1'x1'. In the pre-processing step, the altimetry data especially Geosat and ERS1, were retracked to reduce errors due to the land influence. The main computation step was done by using two different methods, least square collocation (LSC) and Inverse Vening-Meinesz (IVM). The computed gravity anomaly models then assessed with the in-situ marine gravity data from the National Geophysical Data Center (NGDC). The best model in term of RMS error is the 10 km Gaussian filtered LSC with an RMS error of 15.042 mgal. The least accurate model is the non-filtered IVM with an RMS of 16.704 mgal.

The traditionally human-visual or manual interpretation is generally chosen method for spatial feature extraction on map producing process in Indonesia, although the pixel-based feature extraction is used in particular step. The main problem of human-visual method is the dependency to operator capacity. Subjectivity may occur because each operator has different ability. In early 20th century, the image segmentation method was still developing and now Geographic Object-based Image Analysis (GEOBIA) method is introduced to mapping process. Researchers are still developing and applying GEOBIA for many mapping purposes. The advantage of GEOBIA is object-based segmentation which contextually influenced by spatial feature characteristics. GEOBIA provides more meaningful information than traditional pixel-based image analysis by allowing less well-defined edges or borders between different classes. On the resulting maps, there are divisions between different types of object classification, for example where some species of mangroves meet are not generally represented by a single object. The developing of remotely sensed imagery data quality requires the developing of extraction method as well. This article discusses the implementation of GEOBIA for coastal mapping in Indonesia. Some research combined pixel-based and GEOBIA method, and some get the overall accuracy > 70% of GEOBIA method. By developing a new segmentation accuracy measure, we evaluated that segmentation accuracies decrease with increasing segmentation scales and the negative impact of under-segmentation errors become significantly rise at large scale. The use of GEOBIA for coastal mapping in Indonesia are still lacking, locally applicable and still developing the transferability rule sets. The conclusion is that the innovation is needed to make GEOBIA method applicable for mass production of Indonesian coastal map.

Indonesia is known worldwide as an archipelagic country with a vast territory and a country consisting of many islands. The length of the coastline reaches about 81,000 km2, so Indonesia is the largest archipelagic country in the world with two thirds of its territory consisting of oceans. One of the efforts that need to be conducted is to improve the economy and accelerate the development of the marine sector. With this policy, the security of marine and marine resource management is very important. Exclusive Economic Zone (EEZ) and continental foundation are vital areas that need to be guarded and guaranteed for the benefit of maritime sovereignty of the Republic of Indonesia. The development of science and technology of remote sensing, LAPAN in cooperation with IPB to make satellite LAPAN / IPB-A3 or A3LISat. These satellites serve as monitoring of paddy field resources. These satellites are orbiting 14 times a day in the territory of Indonesia is equipped with AIS (Automatic Identification System) sensor where the sensor is to monitor the mobility of the ship. The AIS sensor can provide location coordinate information and temporarily obtain ships vessel information in Indonesian seas. This research tried to utilize the AIS sensor and combined with PFZ (Potential Fishing Zone) information result of remote sensing data and analyzes the mobility of fishing boats recorded by A3 satellite whether it is in accordance with the PFZ information extracted from remote sensing satellite LISat data.

Indonesia is a country that has a large sea area of about 96,079.15 km2. With this condition we can utilize the natural resources that are infested in the sea, such as fish, and salt. Indonesia has exceptional salt pond commodities from various areas such as Cirebon, Sampang, Indramayu Madura, and Rembang. These resources need to be monitor and inventory in proper way. The development of science and technology, there is an effective and efficient way to identify, monitoring and inventory of salt ponds using remote sensing technology. In this last period the saltwater pond infiltration is still inclined to utilize optical sensor system to monitor and infuse. The method used is visual interpretation through multipolarization composite radar image by using interpretation key. The weakness of passive sensors is affected by the presence of cloud cover. The location of salt ponds in Indonesia is mostly located on the coastal regions that is visually affected cloud cover. In addition the use of active sensor is become a challenging for this aspect. This study was conducted to analysis of hues, patterns, and textures in order to recognize the salt pond object using Alos PALSAR Image (Active Sensor). The salt pond object in multi-polarized composite HH-HH / HV composite radar images is recognizable in dark blue with regular pattern plots with characterized by brighter / clear / bright pink ridges.

Flooding often occurs in the lowlands, while the area is usually a rice production centres which affects the rice crop. Rice fields is generally located on fluvial plains and usually located in coastal areas, with relatively lower altitudes than roads or settlements. Physically wetland is an area flooding hazard and wetlands tend to longer floods than surrounding areas. Flood-hazard areas are formed due to sedimentation and usually at the confluence of river. This area is a fertile area for agriculture, has shallow ground water which is well suited for residential and urban areas. Karawang regency is one of the largest producers of rice commodities in West Java, therefore the Karawang regency government faces a challenge in maintaining the level of rice production due to global climate change that worsen the threat of flood hazard, in addition to land use change and increasing population. Based on the results of the spatial analysis from period of 2000 to 2006 the wetland area have been converted up to 7,493 ha. For the period of 2006 to 2015 wetland area have been converted up to 14,416 ha. Utilization of Geographic Information System with a model of Cellular Automata - Marcov Chain is an appropriate method for studying the phenomenon of expansion of build ups land in coastal region. The primary data used in the research is a land cover map of 2000, 2006 and 2015, which were the results of the multispectral classification of Landsat. The prediction of land cover change for the next fifteen years shows a continuous increase in built up area. The expansion of built up area and the possibility of widespread flood hazard areas, have inverse relationship with the decreasing of agricultural land area.

Sea level anomaly (SLA) is one of the oceanic parameters that play a crucial role in the ocean dynamics. In the Indonesian region, spatio-temporal characteristic of SLA is significantly affected by local topographic features of the region. In this research, we investigate long-term variation of SLA over the region based on Topex/Poseidon, Jason-1 and Jason-2 data, during the period of Sept 1992 to January 2017. After removing some geophysical effects, time series of SLA values at each point of the collinear tracks are analyzed. The result show the long term MSSH in Indonesia area have increase from western part of Indonesia to eastern part with range -40 m to 80 m. The long term SST in Indonesia have almost same trend with the deviation from geoid undulation full degree with short wavelength type, and this phenomena represent the local effect such as shallow bathymetry and close sea. And for long term SLA, Indonesia shows positive value that the anomaly increasing with variable from western part to eastern part of Indonesia from 2.5 mm/year until 7 mm/yr.

The satellite data included sea surface height anomaly (SSHA) from AVISO, sea surface temperature (SST) and chlorophyll-a (Chl-a) from Aqua MODIS and Eastern Little Tuna (Euthynnus affinis) catches were used as a combined dataset to understand the ocean variations and further addresses their relations with the Eastern Little Tuna catches in the Java Sea. The fish catches and remotely sensed data were analyzed for the 5 years datasets from 2010-2014. The relationships of oceanographic factors and catch distribution were explored with a generalized additive model (GAM). Catch rates varied temporally relatively significant over year-round. The Eastern Little Tuna catch rates have the peak season in March and October (900 ton to 1000 ton). The ELT catch peaks during the transition season from southeast to northwest monsoon (September to November) and decreases during southeast monsoon (June to August). The GAM results showed that the 3-oceanographic parameter combination models explained the highest deviance (41.4%) with Chl-a explained the highest deviance (23.3%). High probabilities of Eastern Little Tuna catches corresponded to marine productivity of Chl-a concentration ranging from 0.3-0.5 mg/m³, for SSHA ranging from 0-8 cm and SST ranging from 28-29°C. We recommend to have further investigations through the use of long-term historical time series to predict fishing ground locations and an emerging need to improve our climate understanding and forecast skill to conserve small pelagic catches.

The relationship between The Kuroshio velocities and Sea Level Anomalies (SLA) in the upstream areas (between Taiwan and Yonaguni Island) is investigated based on satellite altimetry observation. Mean of the SLA data from 2005-2008 show that in the northeast of Taiwan tends to form strong eddy activity. Furthermore, the type of eddy that forms in the upstream areas is difference every season, cold (warm) eddy more exists in summer (winter). The speed of the Kuroshio in the upstream areas is determined by combination of High-Frequency (HF) radar and Copernicus Marine Environment Monitoring Service (CMEMS) data. These two are exhibited that Kuroshio speed become faster (slower) in summer (winter). High positive correlation of the Kuroshio speed and SLA are found in between Yonaguni and Iriomote Island. When the Kuroshio speed in the middle of HF radar areas (123.375° N) became faster, it coincided with transition of warm eddy to cold eddy in the northeast of Taiwan and vice versa.

The demand for remote sensing imagery data has been increasing in recent years in Remote Sensing Technology and Data Center LAPAN, especially the utilization of such data for the maritime field. Data request is recorded increasing trend from 808 scenes in 2015 to become 6773 scenes in 2016. Therefore, Remote Sensing Technology and Data Center should improve its services so that information provided to users could be delivered as fast as possible. The objective of this research was to find the best alternatives dissemination from the current method of data distribution and remote sensing information in terms of speed, scalability, functionality and data maintenance in order to support government program on maritime sectors. Alternative to be examined was based on Web-GIS which means that access to data and remote sensing information could be done online through internet. The used of Web-GIS in this study due to the utilization of the internet already prevalent in the present day. Through this method, users could have obtained data and information from anywhere and anytime. As an example, this paper uses mangrove distribution data in Banten as remote sensing data provided. Results are easily obtained mangrove information; the government can overcome the problems that has emerged as the reduced area of mangrove forest which resulted in causing chain actions such as floods and other disasters. Using Web-GIS can be an effective means of dissemination to speed up service.

In this paper, a well-known Saint-Venant's Equation is solved by using Predictor-Corrector method to simulate the propagation of wave in shallow water region with several type of bottom friction effects. The predictor step is chosen to be Adam-Bashforth, meanwhile Adam-Moulton for the corrector step. Numerical stability is also discussed by applying von Neumann stability into the linear equations.

Currently oceanographic data can be obtained through overseas websites that provide online and costless, but these online data generally have rough resolution with global or regional space coverage. The purpose of this study is to apply tidal measurements in three different waters (Surabaya, Gresik and Lamongan, East Java-Indonesia) that can transmit data via SMS gateway and store data on the web server to be accessible by people. The first step is to combine the electronic and mechanical circuits and then it was followed by experimental tools and data retrieval conducted in the laboratory. After the trial is successful, it was followed by the actual data retrieval that it tested the transmission of data from the observer station to the data center via modem that uses AT Command, a computer language program. Data will be received and stored in a web server, and then the data can be accessed via internet. The results showed that tidal instrument can work well and gave an estimated error of 3-4%. The choice of location of instrument placement was very important. The most important in this research was to avoid the crowded boat traffic and under the bridge.

The majority of tubular joints commonly found in offshore structures are in the form of multi-planar tubular joints, but very few investigations have been reported due to the complexity and high cost involved. The majority of research have been focused on the study of stress distribution at certain position such as saddle and crown points, and the hot spot stress (HSS) at other position along the weld toe of brace/chord intersection have been ignored. In this paper a 60° two-planar double KT (DKT) tubular joint is modelled as a finite element model from an offshore jacket platform. The effect of dimensionless geometrical parameters on the geometrically stress distribution and SCF distribution along the weld toe of inclined brace in axially loaded on the joint are investigated. Non-dimensional parameters that are varied include β, τ, γ and θ. Validation of the finite element model shown a good agreement to the global structural analysis results. The results of parametric studies show that the increase of the β leads to decrease of SCF. While the increase of the τ, γ and θ leads to increase of SCF. The peak SCF mostly occurs at the outer saddle point. The effect of parameters β, γ and θ on the SCF are greater than the effect of parameters τ.