Kandungan Gas Biogenik dan Termogenik Gas Sedimen Dasar Laut di Perairan Selat Madura. (Pengaruhnya terhadap Sifat Fisik dan Keteknikan)

Sedimen dasar laut di daerah perairan Madura dan sekitarnya umumnya mengandung kandungan gas yang dampaknya terhadap sifat fisik sedimen dasar laut sangatlah signifikan. Hal ini kaitannya dengan rencana peletakan pondasi bangunan infrastruktur di Perairan Selat Madura dan sekitarnya. Berdasarkan hasil yang diperoleh dari pemboran dimulai dari kedalaman 1 hingga 20 m dibawah permukaan dasar laut mengandung gas biogenik.. dengan kandungan metana berkisar 50 hingga 60 ppm sedangkan kandungan propana dan isobutana kurang dari 0,2 ppm. Kedalaman lebih dari 20 m dibawah permukaan dasar laut hingga 60 m adalah gas termogenik. Konsentrasi maksimum gas termogenik berupa propana, isobutana dan etana pada kedalaman 52.85 m berkisar dari 0,1 hingga 8,453 ppm. Dari kedua tipe gas ini tahap pembentukan diagenesanya berbeda akibat pengaruh temperatur yang berbeda, sehingga mempengaruhi stabilitas sifat fisik dan keteknikan sedimennyapun berbeda pula. Untuk itu dalam perencanaan pembangunan infrastruktur kelak perlu diantisipasi dengan keberadaan gas tersebut. Sea bottom sediment in Madura waters and surrounding area in generally contains gas which the impacts to physical and engineering properties of sea bottom sediments are very significant. It is connecting with the place of infrastructure building in Strait Madura waters and surrounding area. Based on core drilling the biogenic gas is already contented starting from surface 1 to 20 m depth. It contents methane around 50-60 ppm, propane and isobutene less than 0,2 ppm. The second is thermogenic gas which place more than 20 m depth until 60 m, the maximum concentrates of thermogenic gas (propane, isobutene and ethane) in 52,85 depth are around 0,1 - 8,453 ppm. From both types, the formation method in diagnoses phase is different, because of different of temperaturet so in influence the stability of physical and engineering properties sediment will be different. For that the plan of infrastructure development should be anticipated by existence of the gas

Kandungan Unsur Tanah Jarang di Perairan Kampar, Riau

Makalah ini membahas tentang sebaran dan kandungan unsur tanah jarang, di Perairan dan pantai Kuala Kampar baik dalam sedimen permukaan maupun di bawah permukaan. Untuk mengetahui dan memahami sebaran unsur tanah jarang di daerah selidikan, empat puluh lima contoh sedimen telah dilakukan analisis unsur tanah jarang. Berdasarkan analisis REE, maka unsur tanah jarang di Perairan Kuala Kampar dan sekitarnya terdiri dari Thantalum (Ta), Neobium (Nb), Zirkonium (Zr) Ytrium (Y) Zirkonium ditemukan dalam seluruh contoh yang dilakukan analisa kimia.. Dalam percontoh sedimen permukaan dasar laut sebaran zirkonium mempunyai kandungan antara 2,8 ppm -130 ppm. Sedangkan dibawah permukaan sedimen dasar laut berdasarkan data bor zirkonium ditemukan dengan kandungan antara 20,1 ppm - 75 ppm. Ytrium ditemukan pada seluruh contoh yang dianalisis kimia. Pada sedimen permukaan dasar laut sebaran ytrium mempunyai kandungan antara 4,1 ppm -39,3 ppm. Sedangkan dibawah permukaan sedimen dasar laut dari data bor ytrium ditemukan dengan kandungan antara 8,6 ppm - 17 ppm. Neobium ditemukan pada 33 percontoh yang dianalisa kimia dengan kandungan antara 0,06 ppm - 15,3 ppm dalam sedimen permukaan dasar laut perairan Kuala Kampar.dengan kandungan tertinggi pada MKP-69 (15,3) ppm. Dari contoh bor neobium ditemukan dalam BH-2 kedalaman bor (11-12m) 5,5 ppm dan BH-3 kandungan kisaran antara 2,6 ppm - 6,9 ppm Thantalum ditemukan dalam 23 percontoh yang dianalisa kimia dengan kandungan antara 1,43 ppm dan 19,3 ppm dengan kandungan tertinggi pada MKP-69. Dari contoh bor (BH-1, BH-2 and BH-3) thantalum tidak ditemukan. Unsur tanah jarang kebanyakan terdapat pada sedimen dasar laut pasir, pasir lanauan dan lanau pasiran. The paper describes distribution and rare earth element contents in surface and sub surface sediments of Kuala Kampar waters area. To find out the distribution of rare earth element in the study area, forty-five samples have been analysed. According to REE analysis the sediments in Kuala Kampar area consist of Thantalum (Ta), Neobium (Nb), Zirconium (Zr) and Ytrium (Y). Zirconium found in all samples of surficial sea bottom sediment. Zirconium content ranged between 2,8 ppm and130 ppm. On the other hand subsurface seabottom sediment from core data shows zirconium content between 20,1 ppm and 75 ppm. Ytrium found in all samples analysed and the content range between 4,1 ppm and 39,3 ppm, while from core data ytrium content between 8,6 ppm and 17 ppm. Neobium found in thirtythree samples chemically analysed, the content range between 0,06 ppm and 15,3 ppm, where the highest content occur in MKP-69. From the core neobium found.in BH-2 core data (11 m - 12m) 5,5 ppm and BH-3 the content range between 2,6 ppm and 6,9 ppm. Thantalum found in 23 samples and the content range between 1,43 ppm and 19,30 ppm, where the highest content occur in MKP-69. From the core (BH-1, BH-2 and BH-3) thantalum is not found Most of Rare earth element generally found in sea bottom sediment: sand, silty sand and sandy silt

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

Diving into the vertical dimension of elasmobranch movement ecology.

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements.</p