Sunda Strait Research Articles

Post-disaster rapid assessment of Sunda Strait tsunami on 24th–25th December 2018 in the Regencies of Serang and Pandeglang, Province of Banten, Indonesia

Post-disaster rapid assessment of the Sunda Strait Tsunami was conducted on 24th–25th December 2018 in five selected sample sites. These study sites were located on the western coast of the Regencies of Serang and Pandeglang, and represented a range of damages, losses, and needs. The aims of this assessment are: (1) measuring the tsunami wave dimensions, (2) observing the landscape conditions, and (3) investigating the affected land cover. The physical damages were investigated based on the tsunami wave dimension analysis, by using a direct-field measurement, drone-based survey, and local interviews. The results show that (1) the greatest trace of tsunami dimensions in Tanjung Jaya Village, Panimbang District, Pandeglang Regency was subjected to the highest fatality, (2) the open landscape aggravated the tsunami impact, compared to the landscape with perennial trees or hilly topography, and (3) the severely destructed buildings were usually on the nearest coastline, where Sambolo residential area in Sukarame Village had the worst impact. These conditions were exacerbated by: (1) the absence of coastal retaining structures as physical defense, and (2) built-on facilities on reclaimed land that violated government regulation. Additionally, this paper proposes several recommendations to support the next phase of mitigation strategies and sustainable planning.

Kebiasaan Makanan Ikan Tembang (Sardinella fimbriata) di Perairan Selat Sunda

Fringescale sardinella is a small pelagic fish in the Sunda Strait which has important ecological value. Studying fish food habits is basically to determine the quality and quantity of fish food and the ecological relationship in the tropic level. The aims of this research were to examine the food habits of fringescale sardinella in the Sunda Strait which includes the composition of the type of food, the area of ​​the niche and the overlap of the food niches. Sampling Sampling was conducted from the catch of fishermen who landed at Labuan Coastal Fishing Port, Banten. Fish samples taken during the study consisted of 620 males and 321 females. The results showed that the highest IP value was in the Thalassiothrix frauenfeldii organism, both in male (55%) and female (54%), so that Halassiothrix frauenfeldii which is a class of Bacillariophyceae was the main food for fringescale sardinella, the largest area of ​​food niches is in male was in the medium size class of 9,0028, while the largest area of ​​food niches in female was in the small size class of 8,9609, the largest overlap value of male and female food niches is in the small fish size group (101-129 mm ) with the medium fish size group (130-158 mm) were 0,9062 and 0,8105 respectively.

Land cover changes, biomass loss, and predictive causes of massive dieback of a mangrove plantation in Lampung, Sumatra

A new massive dieback case of Avicennia marina was observed in the area of the Sunda Strait, which started in 2020, and the cause is still unknown. This research was conducted to report the rate of mangrove degradation, measure biomass loss, and predict the causes of the dieback. A sequential imagery analysis (2019–2022) was conducted to interpret the area changes using a research area of 200 ha from the total 528.69-ha mangrove, using the plant senescence reflectance index (PSRI) and normalized difference vegetation index (NDVI). Field data were collected before and during the dieback event (2020 and 2021) at seven research stations including, live mangroves, partial dieback, and full dieback sites. Biomass loss was measured as standing stock volume (SSV) and total biomass carbon (TBC). A literature study was conducted to predict the cause of the dieback. Based on the results, the mangrove dieback caused a rapid and significant loss of healthy stands (results of the PSRI) and very-high-density stands (results of the NDVI). The rate of healthy stand loss was 13.43 ha month−1 (during July–October 2020) and that of very-high-density stand loss was 14.99 ha month−1 (October 2020–April 2021), which affected 126.62 ha or 24% of the total area (last measurement in January 2022). The SSV before dieback was 118.70 (±46.1) m3 ha−1, but within 14 months, it decreased to 20.8 (±6.0), 79.80 (±52.3), and only 1.0 (±1.0) m3 ha−1 for live, partial dieback, and full dieback stands, respectively. The TBC of live mangroves (before dieback) was 51.6 (±24.4) Mg C ha−1, but within the same period, it changed to 30.70 (±3.80), 69.50 (±14.6), and 51.60 (±9.4) Mg C ha−1 for live, partial dieback, and full dieback stands, respectively. Based on the literature study and field observation, the dieback was probably related to less flushing and long-term inundation by the decrease in rainfall intensity, in addition to nitrogen (NO3−N and NO2−N) enrichment, an over-supply of N from fishpond wastes. Sustainable silvofishery may be introduced to ameliorate water and soil quality.

Efforts to Increase the Digitalization of Navigation Services in the Sunda Strait Traffic Separation Scheme

Efforts to Increase the Digitalization of Navigation Services in the Sunda Strait Traffic Separation Scheme

News about the Sunda Strait Tsunami Disaster: From the Selection of News Sources to the Production Process

Journalists had to deal with varying information from government entities with power in the disaster sector when covering the 2018 Sunda Strait tsunami. Indonesian catastrophe journalism now faces new difficulties as a result of unequal and shifting information. This is especially true when it comes to respecting the rule that information should be presented quickly and accurately in order to mitigate disasters. This study aims to learn more about the journalism practices at KompasTV, CNN Indonesia, MetroTV, and Trans7 in the news production process as well as how journalists select news sources in emergency situations, particularly when a tsunami strikes the Sunda Strait. According to this study's findings, Indonesia's four top mass media outlets place a high value on issues including validating catastrophe information, upholding a journalistic code of ethics, and the skill of journalists covering disasters. Journalists rely on and trust information obtained from government organizations with power over disasters and other mass media. Because it is impossible to ensure the accuracy of the material posted on social media, journalists avoid and do not utilize it.

Indications of transtensional strike slip fault in the Mount Anak Krakatau based on earthquake focal mechanism data

Anak Krakatau volcano in the Sunda Strait was through pyroclastic materials landslide phenomenon that caused by a tsunami wave at the end of December 2018. Tsunami wave hit the west coast of Pandeglang and part of the coast of Lampung. Recent tectonic activity produces an epicenter around Anak Krakatau volcano, a shallow earthquake depth of 10 - 15 km below the surface. These data were collected by the interpretation of remote sensing DEM SRTM images, focal mechanism, bathymetry, and hillslope analysis. Quantitative analysis in determining the movement mechanism of strike slip faults and the damage zone as the trigger for landslides on the southwestern volcano sidewall. The main fault has N153°E / 74°E rake 9° is related to the surface of stress and strain results of synthetic and antithetic faults. It is suspected that the post-eruption caldera of Krakatau Volcano is the remaining surface openings in the 1883 while erupted. Knowledge of the causes of landslides to be prepared to anticipate broken infrastructure, victims, and tourism along the coast of Banten and Lampung.

Too Little, Too Late? Redefining the Legacy of HMAS Perth (I), an Australian Warship Sunk in Indonesian Waters

Australian warship HMAS Perth (I) was sunk during the Battle of the Sunda Strait in 1942, claiming the lives of 353 men. It was not until 2017 that Indonesian and Australian authorities conducted a joint archaeological survey of the site. They found that Perth had been salvaged on an industrial scale, with less than 40% of the vessel remaining. The discovery devastated those with an emotional connection to Perth, and, following strong Australian government advocacy, informed Indonesia’s decision to establish a maritime conservation zone, the nation’s first, around the site. Although the 80 years since Perth sank have been characterized by a lack of official engagement, this article proposes that the recent destruction of Perth is not the end, but the beginning, of a new era of bilateral cooperation, founded on the recognition that the wreck has historical significance for Australia as well as potential benefits for local communities in Indonesia.

Long-Term Trend and Variability of Volume Transport and Advective Heat Flux through the Boundaries of the Java Sea Based on a Global Ocean Circulation Model (1950–2013)

The variability and trend of volume and advective heat flux, in addition to the net inflow and outflow of advective heat flux in the Java Sea for 64 years (1950–2013), along with its relationship with the monsoon, ENSO (El Niño Southern Oscillation), and IOD (Indian Ocean Dipole), have all been studied. A simulation of the 3D hydrodynamic HYCOM (HYbrid Coordinate Ocean Model) with a 1/8° grid resolution was performed in this study. Judging from the simulated results, the seasonal variability, which has a period of 12 months, has a very significant impact on contributing to the variability and trend of volume and advective heat flux, as well as the net inflow and outflow of advective heat flux in the Java Sea for 64 years. This is followed by interannual variability, which has a time range of 1.5–6.5 years, and interdecadal variability, with a period of 21.3–32 years. The interannual variability in the Java Sea is strongly caused by ENSO and IOD. El Niño and a positive IOD caused a weakening of southward transport through Karimata and the Bangka Strait. On the contrary, southward transport strengthened during La Niña and the negative IOD. Furthermore, La Niña and a positive IOD both strengthen (weaken) the transport westward (eastward) in the Sunda Strait (Eastern Java). On the other hand, El Niño and a negative IOD weaken (strengthen) the westward (eastward) transport in the Sunda Strait (Eastern Java). According to the findings, the IOD effect is stronger than the ENSO effect in the Java Sea. The inflow and outflow of volume transport in the Java Sea are in balance, but not the advective heat flux. The advective heat transported through Karimata and Bangka Strait to the Java Sea is up to 0.216 PW, while the total advective heat flux through the outflow straits (Sunda Strait and Eastern Java) is 0.220 PW. Thus, the net advective heat flux out of the Java Sea is 0.004 PW, allegedly obtained from an atmosphere–sea interaction in which the sea received heat from the atmosphere.

RISK COMMUNICATION STRATEGY IN DEALING WITH THE TSUNAMI DISASTER

Umang Beach Club Private Island Resort is located in Sumur village, Pandeglang, Banten. Has a unique location, located at two potential tsunami sources. The first is Seismic, which is at the center of the Sunda Strait megathrust. The second, namely Unsesmic, is located at a distance of about 70km from Mount Anak Krakatu. This study aims to find a risk communication strategy in dealing with the tsunami natural disaster. This study used a qualitative descriptive method and collected data by interviews, documentation and observation. Interviews were conducted with informants, namely local governments and disaster-related institutions. The results of the study found that risk communication strategies in dealing with tsunamis were initiated by common perceptions of the tsunami hazard, setting goals, developing messages, face-to-face communication.

Management Indicators of Layur Fish (Trichiurus lepturus Linnaeus, 1758) in the Sunda Strait

Trichiurus lepturus has an important role at the tropic level and is an economically important fish. The purpose of this study was to examine management indicators in the form of time series of catches per effort (CPUE), asymptotic length over time, exploitation rate, ratio of first caught length (Lc) to first gonad maturity length (Lm), and spawning potential ratio (SPR). ). The research was conducted in the Sunda Strait, samples of fish landed at PPP Labuan, Banten. The analytical method used is long frequency analysis, surplus production model, and SPR analysis. The number of male and female fish observed was 396 and 299 respectively. The minimum length of male layur fish is 438 mm and 421 mm for females. The maximum length of the male layur is 843 mm and the female is 773 mm. CPUE results tend to increase from 0.416 in 2014 to 1.043 in 2019. The exploitation rate (E) of fish is 0.85 which indicates that it has experienced over exploitation. Asymptotic length 938.33 mm. The whitefish caught for the first time at Lc = 579.5 mm had an SPR of 13.10% and at Lm = 718.5 mm it had a fairly high SPR of 31.7%. Catch size occurs before layur fish spawn. SPR below the biological reference point. However, in 2019 there was an increase in catches allegedly due to a pause in fishing due to the tsunami in 2018.

Analysis of dynamic agility orchestration resources as a model for Sunda Strait Coastal tourism recovery

This study aims to do two things: 1) figure out why coastal tourism isn't coming back, and 2) find a way to connect the results of different studies on how tourism affects coastal tourism recovery. Part of the research plan was to do a causal study, which looks for a link between a cause and an effect. Purposive sampling was used to select samples from the study populations of tourism actors in the Sunda Strait and Banten Province. The data were analyzed quantitatively and qualitatively (mixed methods).The IBM SPSS AMOS 21 (Analysis of Moment Structure) and Structural Equation Modeling (SEM) AMOS 21 programs were used to do descriptive analysis and test models and hypotheses. There was a connection between the tsunami disaster and the COVID-19 pandemic. These two things are the main reasons why the Sunda Strait coastal tourism sector is in a crisis, and it is still hard to get out of a crisis like this. Disaster management was shown to have a big, positive effect on the crisis, the way resources are used, and the number of tourists who visit. Tourist visits had a significant impact on dynamic agility orchestration resources and coastal tourism recovery. Also, the tourism crisis helped the coastal tourism industry get back on its feet in a big way. The tourism crisis and coastal tourism recovery benefited significantly from dynamic agility orchestration resources.

Pleistocene Accelerated Exhumation Within the Sumatran Fault: Implications for Late Cenozoic Evolution of Sumatra (Indonesia)

AbstractThe 1,900‐km‐long Sumatran fault plays an important role in accommodating oblique plate motion between the Indo‐Australian and Sunda plates. Although fault geometry, kinematics, and seismic activity are well‐studied, the onset of dextral motion on the Sumatran fault and uplift of adjacent Barisan Mountains is unclear; this hinders an understanding of the late Cenozoic evolution of Sumatra and the forearc region. In this study, we use low‐temperature thermochronology to measure cooling histories of rocks within and outside of the Sumatran fault. An accelerated exhumation within the fault zone began at ∼2 Ma. The Barisan Mountains may have experienced uplift and associated river incision in the late Miocene to Pliocene. The fault systems in the forearc region were inferred to be kinematically linked to the Andaman Sea and Sunda Strait and accommodated early relative plate convergence, then relocated the strike‐slip component of deformation to the Sumatran fault at ∼2 Ma.

Recent Researches of Insular Southeast Asia and the Problem of Srivijaya

Historical geography of early Southeast Asia remains a point at issue since the late nineteenth century. Since George Cœdès discovered ‘The Kingdom of Srivijaya’ in his 1918 paper, its history, chronology, and localization is still a subject of long debates despite a few data available. While the center of Srivijaya may be located in the area of modern Palembang in South Sumatra because of Old Malay and Sanskrit inscriptions and other archaeological findings, there is still a problem of its long-term polity which presumably survived for several centuries, changed its name from Shilifoshi 室利佛逝to Sanfoqi 三佛斉in Chinese texts in the tenth century, controlled the Malacca Strait, fought with Javanese kingdoms and built monasteries in South India. Srivijaya is often called а empire or thalassocracy. The basic methodology implies a juxtaposing of epigraphy, archaeological data, and the Arab and Chinese texts. But one should take into account specific features of any testimony survived as well as one should use historical phonology of Old and Middle Chinese. Recent researches of Stephen Haw, Johannes Kurz, and Liam Kelly offer new interpretations of the Chinese sources which deal with Shilifoshi and Sanfoqi. The present paper gives an overview of recent scholarship of Srivijaya and early Southeast Asian historical geography. Haw’s conclusion that the Sunda Strait was a major maritime route in the fifth to eighth centuries seems well-grounded. Kurz’s statement that Sanfoqi could not be Shilifoshi also seems plausible. But Haw’s phonetic reconstructions are probably not reliable.

The Mount Anak Krakatau landslide scenario for tsunami modeling in Banten

The eruption of Mount Anak Krakatau occurred on December 22, 2018, in the Sunda Straits, Indonesia, causing a tsunami that affected the coastal area of Banten Province. We use COMCOT 1.7 to make a tsunami model based on flank collapse caused by a landslide tsunami. The aim of study is to remodel past events to anticipate the mechanism and impact of the damage in the future. Bathymetry and topography are integrated to become high resolution data with a grid area of 49.8 meterss. The flank collapse scenario is applied with slide dimensions of 2000 meters long, 1500 meters wide, and 228 meters thick following previous study. The tsunami model consists of the initial tide model and the coastal model. The highest tsunami run-up of the tide model is in Carita of 1.9 meters height. The fastest arrival time of the tide model is in Sumur of 19 minutes. which is slightly different from previous studies due to different modeling applications and different initial tide locations. The highest tsunami run-up of the coastal model is in Lesung and Sumur of 2.5 meters height which almost matches the results of field observations.

Dynamic Spatial Model of Settlement Land in Tsunami-Prone Areas, Carita District, Banten

Carita District, Banten was one of the districts affected by the tsunami in the Sunda Strait in 2018. With 2.668 hectares of land cover changing mainly in agriculture and urban areas. The land cover affected by the tsunami in the Carita Area consists of horticulture (24.11 ha), rice fields (2.70 ha) and buildings (4.91 ha). Residential areas, infrastructure and service sectors, especially tourism are also affected. According to the Carita District 2022-2042 RDTR (Detailed Spatial Plan), Carita District is still a tsunami-prone area. The purpose of this research is to provide a residential area forecast with spatial models, patterns, and directions for residential area development in the Carita region over the next 20 years. The method used in this research uses a cellular automata algorithm and a dynamic spatial model that utilizes the results to obtain an analytic hierarchy process score from expertise in the Carita District. Based on the results of the analysis there is an increase in settlements of 697%, some of which expanded in the southern and northern areas of Carita District. The results of the simulations that have been carried out can be input for the Carita District government in the direction of land use development

Distribution of seismicity hazard levels using PGA analysis with the PSHA method in the Ciletuh Geopark Area, Sukabumi, Indonesia

The regional structure in Java Island, Indonesia, was influenced by the collisional activity of the Eurasian and Indo-Australian plates, which resulted from mélange rocks outcrops in Ciletuh. Ciletuh is one of the geotourism conservation areas included in the UGG (UNESCO Global Geoparks). This area is in the path of the Cimandiri Fault and the Sunda Strait Megathrust, resulting in a unique geological diversity and a place where the oldest rocks are exposed in West Java. In addition, the potential impact of seismicity on the Ciletuh geopark area is quite significant. The potential for seismicity can be analyzed and calculated. In this study, PGA (Peak Ground Acceleration) analysis on bedrock was conducted using the PSHA (Probabilistic Seismic Hazard Analysis) method. The data used for the PSHA method is in the form of background, fault, and megathrust provided by the National Earthquake Study Center (PuSGeN). This research shows that the PGA value in the Ciletuh Geopark area is influenced by how close it is to the location of the earthquake source. Pelabuhanratu Subdistrict has the highest PGA value based on all earthquake sources when combined.

PENDEKATAN MODEL STRATEGI KOMUNIKASI BENCANA GEMPABUMI DAN TSUNAMI DI KOTA CILEGON

Cilegon City has tourist resources, international trade, and strategic vital industries, adjacent to the Sunda Strait as an international trade route, but has the potential for earthquake and tsunami disasters from the South Java Megathrust, magnitude 8.7 and tsunami due to the eruption of Mount Anak Krakatau (GAK). In maintaining the existence of resources and reducing the impact of disasters, mitigation, and preparedness efforts are needed, including disaster communication. This research aims to identify and determine the model of disaster communication policy in Cilegeon city with a qualitative research method approach case study, data from in-depth interviews and document searches, and data validation triangulation. The results of the research on the communication model before, during, and after a disaster fulfill the minimum elements of communication (communicator, message, media, and communicant), a two-stage communication model, namely first, communicator, message, media, communicant (opinion leader), and feedback. Secondly, with the second stage of communication, Opinion Leader stage I as a communicator in stage II communication. Stage I communication is more likely to be mass communication while stage II communication tends to be group communication and cross-cultural communication. The results of this study also found the proposition that the performance of Cilegon City disaster communication still needs the commitment of regional leaders, coordination and socialisation, more focus on customers, completeness of communication facilities and infrastructure, media partnerships and inter-regional and situational awareness.

Carbon and nutrient enrichment potential of South Java upwelling area as detected using hindcast biogeochemistry variables

Biogeochemical cycles and ecosystems in the South Java upwelling area respond to physical conditions, the diurnal cycle, intraseasonal variability, and climate variations. Whilst carbon and nutrient enrichment occur annually in response to monsoon driven upwelling, the spatiotemporal trends in chlorophyll-a (Chl-a), nutrient and particulate carbon in response to that upwelling are less well understood. Furthermore, the presence of Indonesian throughflow (ITF) may enhance the biogeochemical dynamics in the area. Our study aimed to assess the carbon and nutrient enrichment in the South Java upwelling area. We evaluated satellite derived and hindcast modeled datasets of biogeochemistry variables such as nutrients, Chl-a, particulate organic carbon (POC), particulate inorganic carbon (PIC), net primary production (NPP), dissolved oxygen (DO), and sea surface temperature. The temporal trends and spatial distributions were assessed to detect potential enrichment that affects the direct or indirect responses. The concentration Chl-a, NPP, POC, nitrate, and phosphate intensified during the July–October period in this region. Silicate showed a different pattern, i.e., the highest concentration occurred from March to May which likely correlated to the ITF. Annually, the highest peak of POC concentration was detected earlier (in September) than that of PIC (in October–November). The spatial distribution of POC on surface waters is also likely to be affected by input from the Java Sea or ITF. The intensified concentration of POC from September to November occurred at the Sunda, Bali, and Lombok Strait outlets. The record shows that the highest POC concentration occurred throughout the year in the coastal area. Carbon and nutrient enrichment occurs from July to November during the upwelling period. This paper discusses the highest positive peaks of biogeochemical parameters during September 2011, 2015, and 2019, which co-occurred with El Niño-Southern Oscillation and Indian Ocean Dipole events. This paper also discusses the potential effect of ITF on the upwelling area and the direct or indirect biological responses of the nutrient enrichment.

Machine learning remote sensing using the random forest classifier to detect the building damage caused by the Anak Krakatau Volcano tsunami

In Indonesia, tsunamis are frequent events. In 2000–2016, there were 44 tsunami events in Indonesia, with financial losses reaching 43.38 trillion. In 2018, a tsunami occurred in the Sunda Strait due to the eruption of the Anak Krakatau Volcano, which caused many fatalities and much building damage. This study aimed to detect the building damage in the Labuan District, Banten Province. Machine learning methods were used to detect building damage using random forest with object-based techniques. No previous research has combined selected predictors into scenarios; hence, the novelty of this study is combining various random forest predictors to identify the extent of building damage using 14 predictor scenarios. In addition, field surveys were conducted two years and nine months after the tsunami to observe the changes and efforts made. The results of the random forest classification were validated and compared with three datasets, namely xBD, Copernicus, and field survey data. The results of this study can help classify the level of building damage using satellite imagery to improve mitigation in tsunami-prone areas.

PENDAMPINGAN MANAJEMEN USAHA UNTUK PENGEMBANGAN UMKM SELEUD DI SAWO JAJAR KOTA MALANG

UMKM are one of the important economic sectors in Indonesia. The fact is that UMKM have played an important role in the Indonesian economy to date. When Covid 19 became a global problem, it happened in 2019. This virus spread to various countries, one of which is Indonesia. One of the economic impacts felt by UMKM players is a decrease in sales turnover. Development of Managerial Insights is a course whose program teaches students to do community service. Which activity is a form of training in the form of Community Service. This community service aims to help UMKM to increase sales. With this problem, we are the students at the Malang State University Master of Management who carry out this service activity which will be carried out from the beginning of September 2022 to the end of November 2022 at UMKM Seleud, which is addressed at Jl. Sunda Strait II D3/24 Sawojajar Malang city. The methods used in socialization and education activities include identifying work programs, training, and mentoring. The results of this series of community service activities are the development of attractive product logos, making business logos, more modern marketing, payments via QRIS and getting distributors hydroponic raw materials.