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KARAKTERISTIK SEDIMEN PANTAI DAN DASAR LAUT DI TELUK PAPELA, KABUPATEN ROTE, PROVINSI NTT
Get PDFPenelitian karakteristik sedimen pantai dan dasar laut Teluk Papela dilakukan untuk mengetahui rona awal lingkungan Teluk Papela. Analisis mineralogi dan granulometri yang dilakukan pada sedimen pantai dan dasar laut, menunjukkan dominasi pasir halus. Sedimen pantai menunjukkan kecenderungan menghalus ke arah utara dengan kandungan cangkang yang semakin besar, sedangkan sampel laut menunjukkan kecenderungan butiran lebih kasar ke arah utara dengan kandungan cangkang yang semakin kecil. Hasil analisis unsur utama menunjukkan bahwa TiO2 (0,1 wt%) dan CaO (82,5 wt%) menunjukkan tingginya pasokan material asal darat. Kandungan unsur jejak Sr, Cl, I dan unsur utama P2O5 dalam sedimen lebih rendah dari kandungan dalam air laut. Pu terdeteksi dalam semua sampel dengan nilai berkisar antara 13.200 dan 28.000 ppm. Korelasi positif Cl-Na2O serta Cl-P2O5 menunjukkan bahwa unsur-unsur tersebut merupakan hasil dari pengendapan garam dalam sedimen. Keterdapatan Sr berkaitan dengan kelimpahan organisme pembentuk cangkang, sedangkan kandungan I dipengaruhi oleh kandungan bahan organik. Keterdapatan Pu dalam sedimen Teluk Papela diperkirakan merupakan hasil aktivitas manusia yang terserap dalam cangkang dan terakumulasi dalam sedimen pantai dan dasar laut.Kata kunci: karakteristik sedimen, unsur utama, unsur jejak, mineralogi, granulometri, Teluk Papela The study of seafloor and beach sediments of Papela Bay is conducted to identify the initial early environment of Papela Bay sediments. Mineralogy and grain size analysis some of selected samples were conducted on coastal and seafloor sediments and they show dominated by fine sand. Coastal sediments show tend to fining northward with increasing skeletal, in contras marine samples tend to show a more coarse northward with a smaller skeletal content. Result of major elements analysis show that the average of weight percentage of TiO2 (0.1 wt%) and CaO (82.5wt%) and indicate that the high supply of material derived from land. Trace elements content of Sr, Cl, I and major element P2O5 within sediment lower than within sea water. Pu detected within all samples with values range between 13,200 and 28,000 ppm. The positive correlations of Cl-Na2O and Cl-P2O5 show that these elements are the result of salt deposition within sediment. The occurance of Sr related with the abundance of shell-forming organisms, whereas the content of I influenced by organic matter content. The occurance of Pu within sediment in Papela Bay can be resulted by antropogenic activities that absorbed and accumulated within coastal and seabed sediments.Key words: sediment characteristics, major element, trace element, grain mineralogy, Papela Ba
Vertical Distribution of Heavy Metals in Coastal Sediment: A Record of the Changing Input in the Estuarine of the Semarang Flood Canal
Get PDFSediment plays an important role in archiving contaminant like heavy metals and couldrecord metal contamination in sediment due to land-based input such as flood canals of Semarang. Thisstudy was to understand the changing record of heavy metals’ contamination in coastal sediment and toassess the sediment quality. Two core sediments, from two different sites, were collected up to 80 cm in depthand, subsequently, sectioned within a 5 cm interval. A digestion system followed by AAS measurement, wasused to determine the metal concentrations, Enrichment Factor (EF) was applied to assess sediment quality.The sediment fraction and metals concentration revealed the changing of input and deposition process alongsediment cores in East Flood Canal (EFC) and West Flood Canal (WFC). There was an alteration ofsediment composition in which the proportion of sediment composition moved to finer size in EFC and apulse of coarser-finer-coarser size of sediment composition was observed in WFC. In general, higherconcentrations of Fe, Cd, Cu, Ni and Zn were observed differently with Pb concentration. Ni along bothsediment cores was unenriched (EF<1), whereas Cd, Cu, Pb, and Zn were classified minor to moderateenrichment. Thus, the source and deposition processes of these Fe, Cd, Cu, Ni and Zn were differentcompared with those of Pb.Keyword: flood canal, Semarang, heavy metal, Enrichment FactorSedimen memiliki peran sebagai tempat penyimpanan bahan pencemar seperti logam berat dan studiatas pencemaran logam berat dalam sedimen di banjir kanal kota Semarang belum banyak dilakukan. Sehinggatujuan dari penelitian ini adalah untuk mengetahui sejarah pencemaran dengan melihat distribusi vertikal kemudianmenilai status logam berat dalam sedimen di muara banjir kanal barat dan banjir kanal timur kota Semarang. Untukmenjawab tujuan penelitian, telah dilakukan pengambilan 2 sampel sedimen inti hingga kedalaman 80 cm kemudiansedimen tersebut diambil tiap interval 5 cm. Metode peleburan yang diikuti pengukuran dengan AAS dilakukanuntuk mengukur konsentrasi logam dan Enrichment Factor (EF) dihitung untuk menilai kualitas sedimen. Fraksisedimen dan konsentrasi logam berat menunjukkan perubahan masukan dan proses deposisi di sepanjang sedimen intiyang dianalsis dari Banjir Kanal Timur (BKT) dan Banjir Kanal Barat (BKB). Tampak adanya perubahankomposisi sedimen dimana sedimen di EFC cenderung menjadi lebih halus sementara tampak adanya fluktuasikomposisi sedimen di WFC dari kasar-halus-kasar. Masing-masing logam menunjukkan pola yang berbedawalaupun konsentrasi Fe, Cd, Cu , Ni dan Zn tinggi tampak di periode energi yang lebih tinggi dan konsentrasi Pbtinggi teramati sema periode energi rendah. Ni di kedua sedimen inti masih berada pada konsentrasi alami(EF<1),tetapi Cd, Cu, Pb dan Zn telah mengalami pengayaan minor hingga moderat. Informasi tersebut dapatmenunjukkan sumber dan proses deposisi Fe, Cd, Cu, Ni dan Zn berbeda dengan Pb.Kata kunci: Banjir kanal, Semarang, logam berat, Enrichment Factor
Oblique Intraplate Convergence of the Seram Trough, Indonesia
Get PDFThe Banda Arc which curves around through 180o is one of interesting features in Eastern Indonesia, a complex area resulting from convergence of Indo–Australia, Eurasia, and Pacific plates with a number of microplates involved. Its complexity has led to debates on how the U–shaped geometry was attained. This study investigates seafloor morphology and seismicity around the Seram Trough which may help to give an insight into the tectonic setting of the area. We further discuss each model proposed for the Seram Trough by previous authors. Generally, there are two views on how many slabs are subducting beneath the Banda Arc, either double slabs or single slab. The Seram Trough, which is often linked to the Timor–Tanimbar Trough enclosing the Banda Arc, was interpreted in different ways, with many models by many authors, as a subduction trench, an intraplate foredeep and a zone of strike–slip faulting. We argue that the most plausible explanation is a single slab model to explain the nature of the Banda Arc. The most plausible model for the Seram Trough is a foredeep model which is associated with exhumation processes on Seram and the deep feature was caused by a subsidence, led by loading by the fold–thrust belt. The Seram Trough is significantly different to common subduction systems. It has shallower bathymetry, is less than 3000 m in depth and is an almost aseismic zone. Keywords: Banda Arc, Buru Basin, convergence, fold–thrust belt, Seram Trough.Busur Banda yang melengkung 180o merupakan fitur menarik di Indonesia bagian timur, suatu area kompleks hasil konvergensi lempeng Indo–Australia, Eurasia dan Pasifik dengan beberapa lempeng mikro terlibat. Kompleksitasnya mengarah pada perdebatan bagaimana geometri ‘U’ terbentuk. Studi ini menginvestigasi morfologi dasar laut dan kegempaan disekitar Palung Seram yang dapat membantu memberikan wawasan tentang tatanan tektonik area tersebut. Kami juga mendiskusikan setiap model yang diajukan untuk Palung Seram oleh beberapa penulis sebelumnya. Umumnya, terdapat dua penjelasan tentang berapa jumlah lempeng yang menunjam dibawah Busur Sunda, antara dua lempeng atau satu lempeng. Palung Seram yang sering dihubungkan dengan Palung Timor-Tanimbar menyelubungi Busur Banda telah diinterpretasikan dengan beberapa model oleh beberapa penulis sebagai palung subduksi, foredeep dalam satu lempeng dan zona sesar mendatar. Kami mengajukan bahwa penjelasan yang memungkinkan adalah model satu lempeng dalam penjelasan keadaan Busur Banda. Model yang dapat diterima untuk Palung Seram adalah foredeep di depan sabuk sesar anjak dan lipatan yang berasosiasi dengan exhumation processes di Pulau Seram dan fitur yang dalam diakibatkan oleh subsidence akibat pembeban jalur sesar anjak dan lipatan. Palung Seram memiliki batimetri yang lebih dangkal, kurang dari 3000m dan merupakan zona aseismik.Kata kunci: Busur Banda, Cekungan Buru, konvergensi, jalur sesar anjak dan lipatan, Palung Seram
STRATIGRAFI PERAIRAN UTARA BALI DARI HASIL INTERPRETASI SEISMIK 2D
Get PDFSecara geografis daerah penelitian terletak pada koordinat 1140 32’ – 1160 01’ Bujur Timur dan 070 15’ - 080 02’ Lintang Selatan. Kondisi geologi dasar laut belum banyak dibahas oleh para peneliti di Perairan Bali Utara, karena kurangnya data seismik dan data sumur bor. Cekungan Jawa Timur di sebelah selatan dibatasi oleh busur vulkanik, sebelah timur dibatasi oleh Cekungan Lombok. Stratigrafi daerah penelitian dari tua ke muda terdiri dari formasi Prupuh, formasi Rancak, formasi Cepu, formasi mundu dan formasi Lidah. Metoda penelitian terdiri dari pengukuran navigasi, pengukuran kedalaman dasar laut, pengukuran seismik 2D serta kesebandingan data seismic dan bor. Tujuan penelitian adalah mengetahui pelamparan Cekungan Jawa Timur utara di Perairan Utara Bali. Dari hasil interpretasi dan korelasi antara data seismik dengan sumur bor, menunjukkan bahwa rekaman seismik 2D daerah telitian dapat dibagi menjadi enam (6) runtunan dengan urutan dari atas ke bawah adalah runtunan A, B, C, D, E, dan F.Kata kunci:Data seismik 2D, interpretasi, Cekungan Jawa Timur, Perairan Utara Bali, Data bor Geographically the research area lies within coordinates of 1140 32’ – 1160 01’ East and 070 15’ - 080 02’ South. The geological condition of the seabed has not been much discussed by researchers in the North Bali Waters, due to the lack of seismic and well data.The East Java Basin to the south is bounded by a volcanic arc, whereas the Lombok Basin on its eastward. Stratigraphy of research area consists of old to young Formation, i.e., Prupuh, Rancak, Cepu, Mundu and Lidah formation. Method consists of positioning, bathymetric, 2D seismic measurement, and compiled by seismic and well data.The purpose of this research is focused to distribution of the northern East Java Basin in North Waters of Bali. From the interpretation and correlation between the seismic and well data, they can divided by six (6) units from top to bottom are: A, B, C, D, E, and F.Keywords: 2D seismic data, interpretation, east java basin, North Bali waters, well dat
Coastal Protection of Southern Part of The Bintuni Bay From Oil Spill: An Environmental Sensitivity Index Approach
Get PDFThe southern part of Bintuni Bay with highly sensitive ecosystem conditions has evolved into an oil and gas industry where potential impacts on coastal and offshore environments need to be anticipated and planned comprehensively for environmental protection from oil spills. The main problem is the determination of areas that are sensitive and vulnerable to oil spills. This study is to analyze the factors and components that affect the level of environmental sensitivity and mapping Environment Sensitivity Index (ESI) to the oil spill. The study was carried out by identifying and assessing each land units of its and use. Land use and land cover are interpreted through the use of satellite imagery with classification methods of guided satellite imagery. Field survey was also conducted in order to improve the accuracy of land use interpretation. Data analysis was performed by spatially by GIS method. The result indicated that ESI can be divided into five categories, are very sensitive (2,395.98 hectares or 2.38%), sensitive (13,133.53 hectares or 13.07%), moderately sensitive (17,902.78 hectares or 17.81%), low sensitive (52,409.14 hectares or 52.14%) and not sensitive (14,681.48 hectares or 14.61%). Although the study area is dominated by low sensitivity category, however the coastal protection from oil spill still should be prioritized.Keywords: coastal protection, Environmental Sensitivity Index, Oil Spill, Bintuni Bay Wilayah bagian selatan Teluk Bintuni dengan kondisi ekosistem yang sangat sensitif telah berkembang menjadi industri minyak dan gas dimana potensi dampaknya terhadap lingkungan pesisir dan lepas pantai perlu diantisipasi dan terencana secara komprehensif untuk perlindungan lingkungan dari kemungkinan tumpahan minyak. Masalah utamanya adalah penentuan daerah yang sensitif dan rentan terhadap tumpahan minyak. Penelitian ini menganalisis faktor dan komponen yang berpengaruh terhadap tingkat sensitivitas lingkungan dan pemetaan Indeks Sensitivitas Lingkungan (ISL) terhadap tumpahan minyak. Studi ini dilakukan dengan cara identifikasi dan penilaian unit lahan pada setiap penggunaan lahan. Penggunaan dan penutup lahan diinterpretasikan melalui penggunaan citra satelit dengan metode klasifikasi citra satelit terbimbing. Guna meningkatkan akurasi interpretasi penggunaan lahan juga dilaksanakan survei lapangan. Analisis data hasil penilaian unit identifikasi dilakukan secara spasial dengan metode SIG. Hasil penelitian menunjukkan bahwa ESI dapat dibagi menjadi lima kategori, yaitu sangat sensitif (2.395,98 hektar atau 2,38%), sensitif (13.133,53 hektar atau 13,07%), cukup sensitif (17.902,78 hektar atau 17,81%), sensitif rendah (52,409.14 hektar atau 52,14% dan tidak sensitif (14.681,48 hektar atau 14,61. Meskipun sebagian besar daerah daerah penelitian termasuk dalam kategori sensitif rendah, namun demikian perlindungan dari tumpahan minyak harus tetap diprioritaskan.Kata Kunci: perlindungan pantai, Indeks Sensitivits Lingkungan, tumpahan minyak, Teluk Bintuni
Channel Controlled Foraminiferal Distribution off Bakkhali, West Bengal, India
Get PDFStudy area is situated 8 km south of the Bakkhali Island, West Bengal of India and its subaqueous environment influenced by the fluvial processes such as Hooghly River in west and its distributary like Muri Ganga in the centre and Saptamukhi River in the east. To understand the submarine behavior of these channels and associated meiobenthos, total of 28 sediment samples have been studied in detail. The study reveal that a total of fifteen species of recent benthic foraminifera belonging to 13 genera under 11 families were present and their distribution mainly controlled by channel morphology and sediment character. Based on the distribution of these benthic foraminiferal species, two assemblages have been identified. First assemblage, observed within the Hooghly and Muri Ganga channel, where salinity is comparatively low and sediment is mainly dominated by silt and clay. The most dominating benthic foraminifers of this assemblage are Ammobaculites agglutinans, Cribrostomoides jeffreysii and Asterorotalia trispinosa. Whereas, second assemblage mainly comprise of A. trispinosa, Ammonia beccarii, Asterorotalia spp., Elphidium excavatum, Elphidium crispum and Ammonia tepida noticed over the sand bars and adjoining shallow area. Keywords: channel morphology, Muri Ganga, Hooghly, sand ba
PENGARUH AKTIFITAS ANTROPOGENIK TERHADAP SEBARAN DAN JUMLAH JENIS POLISIKLIK AROMATIK HIDROKARBON (PAH) DALAM AIR LAUT DAN SEDIMEN DI PERAIRAN TELUK JAKARTA
Get PDFTeluk Jakarta adalah perairan yang terletak di Daerah Khusus Ibukota Jakarta dan Jawa Barat serta persisnya di pantai utara Propinsi Banten. Di perairan ini bermuara tiga belas sungai yang membawa berbagai macam limbah yang berasal dari daratan menuju ke perairan Teluk Jakarta. Berbagai aktivitas terdapat di perairan ini, antara lain sebagai tempat mencari ikan bagi nelayan, pariwisata, dan pelayaran. Selain itu, di perairan ini juga terdapat pelabuhan laut internasioal Tanjung Priok. Polisiklik Aromatik Hidrokarbon (PAH) adalah salah satu parameter kualitas lingkungan perairan. Penentuan kadar PAH dalam air dan sedimen di perairan Teluk Jakarta telah dilakukan pada bulan Juli-Agustus 2015. Ada tiga titik kawasan, yaitu kawasan barat, tengah dan timur. Tujuan penelitian ini adalah untuk mengetahui sebaran kadar dan jumlah jenis PAH di perairan Teluk Jakarta dan menambah data base inventarisasi PAH Perairan Indonesia. Kadar PAH diukur dengan Gas Chroromatografi – Flame Ionisasi Detector (GC-FID) yang dilengkapi dengan kolom kapiler HP1. Hasil yang diperoleh menunjukkan bahwa sebaran kadar PAH total dalam air laut di kawasan barat berkisar antara 0,007-0,056 ppb, dengan rerata sebesar 0,019 ppb, di kawasan tengah berkisar antara 0,009-0,081 ppb dengan rerata sebesar 0,033 ppb, di kawasan timur berkisar antara tidak terdeteksi (ttd)-0,03 ppb dengan rerata sebesar 0,011 ppb. Kadar total PAH dalam sedimen di kawasan barat berkisar antara 1,1983-7,9750 ppm, dengan rerata sebesar 2,9127 ppm, dikawasan tengah berkisar antara 1,6229-8,2591 ppm, dengan rerata sebesar 4,7049 ppm, dan dikawasan timur berkisar antara 1,597-2,9661 ppm dengan rerata sebesar 2,1224 ppm. Berdasarkan hasil penelitian ini, kadar PAH dalam perairan Teluk Jakarta (kawasan barat, tengah dan timur) belum melebihi Baku Mutu Kualitas Perairan yang dikeluarkan oleh Kantor Kementerian Negara Lingkungan Hidup 2004. Demikian juga untuk kadar PAH dalam sedimen, ditemukan 15 jenis PAH di Teluk Jakarta.Kata kunci: Teluk Jakarta, Polisiklik Aromatik Hidrokarbon (PAH), lingkunganJakarta Bay is located in northern of Jakarta,West Jawa, and Banten rovince. Jakarta Bayis throughten by 13 rivers which coming out and carry out kind of waste from land runoff. Many activities was happened such as fishing, tourisme, shipping and an international sea port, Tanjung Priok. Polycyclic Aromatic Hydrocarbon (PAH) is one of marine environment quality parameters. Determination of PAHs in seawaters and sediments were conducted in July-August 2015. Sampling site was divided in three region: west (Banten), middle (Jakarta) and east (West Jawa). The aim of the research is to determine the distribution levels and kind number of PAH and inventory data base of PAH in Indonesian seawaters. PAH levels measured by Gas Chromatography - Flame Ionization Detector (GC-FID) equipped with a capillary column HP1. The results showed that the levels of PAH total in sea water in the western region ranged from 0.007 to 0.056 ppb, with an average of 0,019 ppb, in the middle range between 0.009 to 0.081 ppb with an average of 0.033 ppb, and in eastern region ranged undetected to 0.030 ppb with an average of 0.011 ppb. Levels of total PAHs in sediments in July-August in the western region ranged from 1.1983 to 7.9750 ppm, with an average of 2.9127 ppm, the central region ranges from 16.229 to 8.2591 ppm, with an average amounted to 4.7049 ppm, in the eastern region ranged between 1.5972 – 2.9661ppm with an average of 2.1224 ppm. PAH concentration seawaters and sediment in Jakarta Bay (west, middle and east region) is not exceed of the Quality Standard Water Quality which issued by Ministry of Environment 2004. Number of kinds PAH was found 15.Keywords: Jakarta Bay, Polycyclic Aromatic Hydrocarbon (PAH), environmen