cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Unknown,
Unknown
INDONESIA
BULLETIN OF THE MARINE GEOLOGY
Published by Marine Geological Institute of Indonesia
ISSN : 14106175     EISSN : 25278843     DOI : -
Core Subject : Science,
Earth & Planetary Sciences
Bulletin of the Marine Geology is a scientific journal of Marine geoscience that is published periodically, twice a year (June and December). The publication identification could be recognized on the ISSN 1410-6175 (print) and e-ISSN: 2527-8843 (on-line) twice a year (June & December) and it has been accredited by Lembaga Ilmu Pengetahuan Indonesia (Indonesian Institute of Sciences) by Decree Number: 818/E/2015. As an open access journal, thus all content are freely available without any charge to the user. Users are allowed to download, and distribute the full texts of the articles without permission from the publisher.
Arjuna Subject : -
Articles 180 Documents
 13   14   15   16   17 
SEDIMENTATION RATES AND CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY OF THE NANGGULAN FORMATION, KULON PROGO, INDONESIA Resti Samyati Jatiningrum; Rivdhal Saputra; Gaudensia Phang; Tokiyuki Sato
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 1 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.1.2022.766

Abstract

The Nanggulan Formation is the oldest sedimentary rock of Paleogene age that was deposited in the eastern part of the Southern Central Java Basin. A total of 103 nannofossil samples were taken from two traverses in the study area, i.e., the Watupuru and Jetis Routes. Based on the biodatum identified from the nannofossil samples, the biostratigraphy of the rock formation is divided into five zonations, namely the upper part of Zone NP16, Zone NP17, the lower part of Zone NP18, the upper part of Zone NP22, and the lower part of Zone NP23, expanding from 41.1 Ma to 32.2 Ma of age (Middle Eocene to Early Oligocene). Only Zone NP17 is identified as a complete zone, whereas the other four are observed as partial. The fluctuation of global sea level is believed to be an influence on the deposition of the Nanggulan Formation. The sedimentation rate and the change of nannofossil species shows a decrease of oligotrophic (Sphenolithus) and an increase of eutrophic (Reticulofenestra) taxa, especially in small reticulofenestrids (Reticulofenestra spp.). This occurrence suggests a shift in the environmental conditions from an oligotrophic condition around 41.1 Ma to a eutrophic one, particularly after 40.40 Ma. The enhanced eutrophication in the Watupuru and Jetis Routes was caused by an increasing terrigenous input in 40.40 Ma and after, consequently providing nutrient availability on the water surface. This interpretation is supported by the increase in the sedimentation rate when sea level slightly decreased in 40.40 Ma.
MARINE GEOMAGNETIC ANOMALY BELT AND ITS RELATIONSHIP TO THE REMNANT ARCS IN THE NORTHWESTERN JAVA SEA, INDONESIA Dida Kusnida; Lukman Arifin
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 1 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.1.2022.773

Abstract

The continuous marine geomagneticsurvey within a timeintervalof1-secondsampling and a precision of 0.1 nT was conducted in the northwestern Java Sea to identify and interpret the general trend of total marine magnetic anomalies and the possibility related to thegeological resourcepotential. These magnetic data were then processed according to the formula corrected and applied to marine magnetic data. The total marine magnetic anomalies of the northwestern Java Sea indicate a well-defined lateral trend belt of anomaly contours. Anomalies are divided into four delineation zones: Zones I, II, III, and IV. A preliminary analysis of these anomalies led to the interpretation, reflecting the residual of a slightly east-west trending geological body underneath.Examination of magnetic anomalies suggests Zone I and IV characterize a basinalarea, Zone II depicts a granitic belt, and Zone III describes a Cretaceousmagmatic arc system in the east that extends from Middle Java across the Java SeathroughSouthern Kalimantan. These magnetic anomalies seem to coincide with the free air gravity anomalies data derived from TOPEX satellite data.  
PB RATIO ANALYSIS OF FORAMINIFERA TO OBSERVE PALEOCEANOGRAPHIC CHANGES DURING HOLOCENE IN ARAFURA SEA Swasty Aninda Piranti; Luli Gustiantini; Shaska R. Zulivandama; Catur Purwanto; Lia Jurnaliah; Budi Muljana; Rina Zuraida; Sangmin Hyun
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 1 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.1.2022.771

Abstract

Arafura Sea is influenced by several climatic dynamics, it is also a part of the coral triangle that provides most of marine organism diversity of the world. Therefore, this area is an important  waters that impact the climatic dynamic so its paleoceanographic changes need to be understood. For that, we analyzed the foraminiferal PB ratio from marine sediment core ARAFURA-24 with a core length of 179 cm, collected from 47.4 m water depth, combined with that of Aru-07, taken from 276 m water depth (core length 152 cm). Both sediment cores were collected from the Arafura Sea using a gravity corer on board Geomarin III. ARAFURA-24 was sub-sampling in every 20 cm interval, while Aru-07 had been prepared in every 10 cm interval. PB Ratio values from ARAFURA-24 and Aru-07 ranged from 0,56% - 7,43% and from 29,89% to 82,66%, respectively. The age model was reconstructed by 14C radiocarbon dating derived from organic sediment, combined with tie points of PB ratio records. The result indicates that ARAFURA-24 has been sedimented since the last 9.7 kyr BP. PB ratio records reveal three maximum sea level rises, which are before 7.4 kyr BP, at 5.86 kyr, and after 3 kyr BP (approximately at 2 kyr BP at Aru-07). From the age model reconstruction, sedimentation during the last 3 kyr BP was relatively slower than that in the older period. It can be concluded that the foraminiferal PB ratio during Late Holocene was not significantly impacted by sedimentation rate (hence detrital influence), in contrast, during Mid-Holocene detrital influence had more impact on the PB ratio record.
MULTI-MODEL VARIATION OF THE ENHANCED ASIAN RAINFALL AND CONTINENT-OCEAN THERMAL GRADIENT FROM PRE-INDUSTRIAL TO MID-HOLOCENE Adinda Maharani; Yudha Setiawan Djamil; Rima Rachmayani
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 1 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.1.2022.762

Abstract

Rainfall over the Asian continent during the mid-Holocene was higher than today as shown by the rainfall proxy records. During the mid-Holocene, increased rainfall over the Asian Continent has been suggested to be associated with the strengthening of the Asian Summer Monsoon (ASM) following a sharper continent-ocean thermal gradient. This study examined multi-model variation between changes of the continent-ocean thermal gradient and the increased rainfall over Asia during the mid-Holocene as compared to the pre-Industrial. We analyzed surface temperature, precipitation, and wind at 850mb from nine Global Climate Models (GCMs) which are all obtained from the database of the Paleoclimate Modeling Intercomparison Project Phase-3 (PMIP3). Multi-model analysis shows that changes in a continent-ocean thermal gradient has a positive correlation with ASM wind. However, a negative correlation occurs between changes in the continent-ocean thermal gradient with Asian rainfall. Models that simulate large changes in the continent-ocean thermal gradient produced the smallest increase in the Asian rainfall and vice versa. Such inverse relation is likely due to the cooling of Indian Ocean SST since its correlation scores with Asian rainfall is much higher than the one with the warming of the Asian continent. Thus, multi-model variation of the increased rainfall over the Asian continent between mid-Holocene and today is mainly related to the multi-model variation of the cooling in the Indian Ocean SST.
SPATIAL DISTRIBUTION OF CHLOROPHYLL-A AND NUTRIENTS IN THE TENGAH ISLAND, KARIMUNJAWA INDONESIA Rikha Widiaratih; Agus Anugroho Dwi Suryoputra; Gentur Handoyo; Eridhani Dharma Satya
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 2 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.2.2022.782

Abstract

Tengah Island is located between Sintok Island and Cilik Island in Karimunjawa, Jepara Regency, Central Java. Tengah Island is one of the zones for the use of marine tourism, which has the allure of attractive spots for snorkeling and diving for tourists. Coral reefs require chlorophyll-a, which is in this case produced by zooxanthellae, as a photosynthetic pigment. The chlorophyll-a concentration is influenced by many factors, including nutrients and environmental parameters. This study aims to see the spatial distribution of chlorophyll-a on Tengah Island and its relationship to nutrients, including ammonium, phosphate, and nitrate, as well as environmental parameters, namely Total Suspended Solid (TSS), salinity, pH, Dissolve Oxygen (DO), temperature, and brightness. Chlorophyll-a is analyzed using the APHA standard (2005), while nutrient analyses for ammonium, nitrate, and phosphate employ the UV-Vis spectrophotometer and Nessler reagent, the APHA 4500-No.3-B (2017), and the APHA 4500-P B, C (2017), respectively. TSS is obtained from Sentinel-2A data processing. The correlation between each dataset was carried out by a method of statistical analysis called Principal Component Analysis (PCA). The results showed that chlorophyll-a had a close relationship with ammonium (r=0.826), brightness (r=0.492), and TSS (r=-0.979). The highest chlorophyll-a concentration of 1,063 μg/L was obtained at Station 1, which is the jetty area and the closest to the mainland. This finding is supported by maximum ammonium, sourced from domestic waste and microbial activity, and good brightness, required by chlorophyll-a for photosynthesis processes.
GEOMORPHOLOGY OF SMALL ISLANDS AND ITS SEAFLOOR PROFILES IN THE EASTERN AND WESTERN HALMAHERA WATERS Abdul Motalib Angkotasan; Dietriech G Bengen; I Wayan Nurjaya; Neviaty P Zamani; Nyoman M.N Natih; Franto Novico
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 2 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.2.2022.774

Abstract

The geomorphology of small islands in the eastern and western parts of Halmahera Island encompasses diversities of geological processes, island forms and types, and topography. The typology of the small islands to the west of Halmahera Island is volcanic and are categorized as hilly islands. To the east, there are coral islands classified as flat islands with smaller area contrast to volcanic ones. This study aims to analyze the land mass elevation of the small islands and the sub-bottom profiles in the eastern and western Halmahera waters. Island elevation data was obtained from Sentinel-2B imagery, whereas seafloor topographic data was acquired from direct field measurements using a GPS sounder. First, the image data underwent atmospheric, radiometric, and sunlight corrections, while the actual depth was estimated through bathymetry correction using tidal data. Then, QGIS version 3.16.6 and ArcGIS version 10.8 were used to analyze the data. The results show that the slope degree of volcanic islands is higher and their seafloor topography is steeper than that of coral islands. The slope degree of Ternate, Maitara, Tidore, and Hiri Islands, abbreviated as Termadoreh, is more than 30o with elevation of more than 100 meters, characterizing hilly islands. While there is only Pakal Island in Buli Bay that has a slope of 33o and the highest elevation of only 100 meters, it is nevertheless considered a flat island. Significantly, the different typologies indicate different morphogenesis and sub-bottom topography; i.e., volcanic islands have higher slope degrees and steeper seafloor profiles compared to coral islands.
DISTRIBUTION OF BENTHIC FORAMINIFERA IN THE WATERS FROM OFF PUTRI ISLAND, NORTHERN BATAM, RIAU ARCHIPELAGO Resti Samyati Jatiningrum; Anggun Mutika; Luli Gustiantini; Nineu Yayu Gerhaneu; Godwin Latuputty; Agustina Rosi Divina
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 2 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.2.2022.783

Abstract

Putri Island is the outermost island bordering Singapore, located north of Batam City, Riau Archipelago Province. A total of 29 sediment samples were collected from the seafloor off Putri Island for foraminiferal study. The purpose of this study is to determine their abundance and distribution related to previous data of environmental conditions. For this study, we analysed quantitative analysis of benthic foraminifera including its abundance, diversity, dominance, and evenness indices. The results denoted that benthic foraminifera was composed of 62 species that belonged to 31 genera. The diversity index was categorized as a moderate to high diversity index (1.85-3.12), with a low to high evenness index (0.37 – 0.78), and a low dominance index (0.05-0.24). This indicates that in general the waters of Putri Island are considered to have a fairly good environment and are quite stable for foraminiferal growth. A slight environmental stability degradation occurred in the north eastern part of the study area which demonstrates high levels of pollutants in the waters. This situation influent the benthic assemblages which are indicated by lowering index diversity at that location.
GEOLOGICAL INTERPRETATION OF THE OFFSHORE SEDIMENTARY BASIN OF NORTH CENTRAL JAVA BASED ON SPECTRAL ANALYSIS AND 2D GRAVITY MODELING Restu Ningsih; Imam Setiadi; Riza Rahardiawan; Ordas Dewanto; Rahmi Mulyasari
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 2 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.2.2022.788

Abstract

The offshore sedimentary basin of North Central Java is a marine basin located in the northern part of North Serayu Basin. This basin was formed through the uplift of the southern part of Central Java (Bumiayu) caused by the movement of a pair of horizontal faults. Studies of sub-basin delineation and basement configuration are rarely carried out in this basin. Therefore, the gravity method referring to subsurface-density variations was carried out to obtain this information. This research aims to delineate sedimentary basins and interpret the geological subsurface based on gravity data using spectral analysis, highpass and lowpass filters, also 2D gravity modeling. An average estimation depth to the basement in the study area of about 2.22 km was determined using spectral analysis. Qualitative analysis shows the basement-high pattern, sub-basin, and structure lineament patterns. The 2D model shows three layers consisting of the upper sedimentary layer of Tertiary-Neogene and the middle layer of Tertiary-Paleogene sediment with a density value of 2.3 gr/cc and 2.5 gr/cc, respectively. The lower layer has the highest density of 2.67 gr/cc, assumed as a granitic basement. The results of the Second Vertical Derivative (SVD) analysis on the residual anomaly cross-sectional paths indicate the presence of thrust and normal faults which can be used to assist the interpretation of fault structures in subsurface geological models. Gravity analysis of the offshore North Central Java sedimentary basin indicates the occurrence of sub-basins and geological structure patterns that considered as a potential zone for the development of the petroleum system in this area.
GEOLOGICAL INTERPRETATION OF 2D GRAVITY MODELING IN TULUNG SELAPAN AREA AND SURROUNDINGS, SOUTH SUMATRA BASIN Eddy Mirnanda; Vera Sarah Simatupang; Harkins Prabowo
BULLETIN OF THE MARINE GEOLOGY Vol 37, No 2 (2022)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.37.2.2022.796

Abstract

The South Sumatra Basin is a prolific oil and gas basin. The Tulung Selapan area, which is to the east and part of the South Sumatra Basin, is considered to have hydrocarbon potential. Several sub-basins, including the South Palembang and the North Palembang sub-basins, exist in the region. One of the geophysical methods for determining the presence of sedimentary sub-basins, structural patterns, and bedrock is the gravity method. The purpose of this study is to determine the structural pattern and interpret the subsurface geological model of the Tulung Selapan area using 2D modeling. The complete Bouguer anomaly (CBA) reveals circular and relatively northwest-southeast trending patterns, ranging from +33 mGal to +62 mGal. 2D gravity forward modeling results in eight successive rock layers. From top to bottom, the uppermost layer is swamp sediment with a mass density of 2.1 g/cm3, followed successively by the sedimentary rocks of the Kasai Formation (2.28 g/cm3), the Muara Enim Formation (2.32 g/cm3), the Air Benakat Formation (2.39 g/cm3), the Gumai Formation (2.3 g/cm3), the Baturaja Formation (2.48 g/cm3), and lastly a layer with a density of 2.7 g/cm3, which represents the bedrock. Due to the limited depth of 2800 m in 2D forward modeling, it is unable to identify the source and reservoir rocks. The seal rock (caprock) is interpreted to be shale from the Gumai Formation at an average depth of 1.53 km. Based on Second Vertical Derivative (SVD) analysis, 2D modeling identifies the presence of geological structures with normal faults.
STUDY OF POTENTIAL INSTALLATION OF OCEAN THERMAL ENERGY CONVERSION (OTEC) IN THE NORTH WATERS OF LEMBATA, NTT Gisela Malya Asoka; Denny Nugroho Sugianto; Yani Permanawati
BULLETIN OF THE MARINE GEOLOGY Vol 38, No 1 (2023)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.38.1.2023.789

Abstract

Ocean thermal energy conversion is an attempt to convert potential energy in the variances heat content of seawater into other energy by utilizing the temperature change between the sea surface and deep sea at least 20°C. The Lembata waters is near to the equator, sea surface temperature tends to be warm and stable. This research was conducted to estimate the potential energy generated from a closed cycle OTEC system in North Lembata Waters. This study used temperature data from Global Ocean Physics Reanalysis from Copernicus Marine Environment Monitoring Service (CMEMS) for 9 years (2012-2020) in 6 stations. Validation was performed using the primary CTD Lembata OTEC Team of the Marine Geological Institute (MGI). Temperature data validation results on the MSE (Mean Square Error), RMSE (Root Mean Square Error), and MAPE (Mean Absolute Percentage Error) methods are considered to represent field temperature conditions. The variability value shows the station point in the North Lembata Waters has a temperature with slight differences. The vertical temperature change (ΔT) shows between 20.98°C to 23.44°C. Potential electric power resulting from the OTEC system using the technical estimation formula. The average net power generated from those temperature gradients ranges from 5.65 MW-7.56 MW, respectively. The Lembata waters have temperature conditions suitable for OTEC installations. Station C-4 has a power potential of 6.84 MW with a depth of 763 m and the distance of 1.86 km from the coastline. Station C-4 in the Omesuri sub-district is the best point for OTEC installation in North Lembata Waters.

Page 15 of 18 | Total Record : 180

 13   14   15   16   17 

Filter by Year

2007 2025


Reset
Filter By Issues
All Issue Vol 40, No 2 (2025) Vol 40, No 1 (2025) Vol 39, No 2 (2024) Vol 39, No 1 (2024) Vol 38, No 2 (2023) Vol 38, No 1 (2023) Vol 37, No 2 (2022) Vol 37, No 1 (2022) Vol 36, No 2 (2021) Vol 36, No 1 (2021) Vol 35, No 2 (2020) Vol 35, No 1 (2020) Vol 34, No 2 (2019) Vol 34, No 1 (2019) Vol 33, No 2 (2018) Vol 33, No 1 (2018) Vol 32, No 2 (2017) Vol 32, No 1 (2017) Vol 31, No 2 (2016) Vol 31, No 1 (2016) Vol 30, No 2 (2015) Vol 30, No 1 (2015) Vol 29, No 2 (2014) Vol 29, No 1 (2014) Vol 28, No 2 (2013) Vol 28, No 1 (2013) Vol 27, No 2 (2012) Vol 27, No 1 (2012) Vol 26, No 2 (2011) Vol 26, No 1 (2011) Vol 25, No 2 (2010) Vol 25, No 1 (2010) Vol 24, No 2 (2009) Vol 24, No 1 (2009) Vol 23, No 1 (2008) Vol 22, No 1 (2007) More Issue