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Abstrak :
ABSTRAK
The relation between spatial variability and residence time for gases in the atmosphere is studied using a two-dimensional numerical model, Results indicate that although the residence time shows a strong dependence on the variability, other factors mainly the distribution of sources, also play an important role. If nothing is known about the location of the sources and sinks, the uncertainty in the estimate of the residence time from variability measures will be at least a factor of 10. The situation is greatly improved when one has indications of where the sources is located. Verification of the model, using gases in the atmosphere for which variability estimates and independent estimates of the residence time were available, proved difficult because of the uncertainties associated with these estimates. The general features of decreasing variability with increasing residence time and a strong dependence on the source configuration were, however, confirmed.

Abstrak :
ABSTRAK Penelitian ini bertujuan untuk menentukan model struktur kecepatan gelombang P, koreksi stasiun dan kajian tektonik tiga wilayah BMG ( BMG Wilayah I - III ). Model struktur kecepatan dan koreksi stasiun ditentukan dengan metoda inversi kuadrat terkecil. Sedangkan kajian tektonik dilakukan berdasarkan analisis distribusi hiposenter dan stres gempa dari data mekanisme fokus. Model struktur kecepatan yang dihasilkan umumnya lebih cepat dari pada model struktur Jeffrey-Mien maupun model Curray dan Fauzi kecuali pada kedalaman 0-34 km. Kecepatan gelombang P pada kedalaman 0-34 km untuk BMG Wilayah I lebih lambat dari pada BMG Wilayah II dan lebih Iambat dari pada BMG Wilayah III. Koreksi stasiun berkisar antara -0,96 hingga 0,22 detik untuk BMG Wilayah I, -0,19 hingga 0,43 detik untuk BMG Wilayah II dan -0,23 hingga 0,10 detik untuk BMG Wilayah III. Kemiringan penunjaman lempeng tektonik BMG Wilayah I berkisar antara 44 ° - 50 0, BMG Wilayah II antara 53 ° - 65 ° , sedangkan BMG Wilayah III antara 60 ° - 65 Stres gempa BMG Wilayah I bagian Tenggara cenderung berarah Selatan Barat Daya - Utara Timur Laut dan berubah ke Barat Laut - Tenggara di bagian Barat Laut. Pada bagian Barat BMG Wilayah II stres gempa cenderung berarah Selatan Barat Daya - Utara Timur Laut dan semakin ke Timur bergeser ke arah Barat Laut - Tenggara. Sedangkan di BMG Wilayah III mempunyai dua pola, yang cenderung berarah Timur - Barat pada daerah yang makin ke Timur, yang mungkin disebabkan oleh perubahan arah penunjaman. Stres gempa yang dominan pada BMG Wilayah I kedalaman 0 - 150 km adalah down dip compression, pada BMG Wilayah II kedalaman 0 - 100 km adalah down dip compression , dan pada kedalaman 100 - 300 km adalah down dip tension . Sedangkan pada BMG Wilayah III kedalaman 0 - 100..km adalah down dip compression, 100 300km down dip tension dan pada kedalaman yang lebih dari 300 kin adalah down dip ' compression.

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ABSTRACT Velocity Structures, Station Corrections And Study For The Tectonic Of Three Meteorological And Geophysical Regions (Sumatera, Java And Nusatenggara)We have determined the model of P-wave velocity structures, station corrections and study for the tectonic of three Meteorological and Geophysical Regions ( Region I, II and III). P-wave velocity structures and station corrections have been computed by the method of the least-squares inversion , whereas the tectonic research has been done by analysis of hypocenters and stress distributions. The obtained velocity structure model was lower than.the model of Jeffrey-Sullen, or Curray and Fauzi for 0 - 34 km deep and faster for the deeper layer. P-wave velocity at 0-34 km deep for the Region I was lower than the Region II and Region III. The station corrections were obtained -0.96 to 0.22 seconds for the Region I , -0.19 to 0.44 seconds for the Region II and -0.23 to 0.10 seconds for the Region III. The dipping of the tectonic plate of Region I was 44°-50 °, Region II was 53 0-65 ° and Region III was 60 °-65 °. Stresses at Southeast of Region I had trend to Southsouthwest - Northnortheast direction and changed to Northwest-Southeast at Northwestern part. In the Western of Region II stresses had trend to South southwest - Northnortheast and changed to Northwest - Southeast at the Eastern part, while in Region III had two patterns with trend to East - West direction at Eastern part, due to the change of direction of subduction. In Region I the down-dip compression dominated the slab down to the depth of 150 km. In Region II the down-dip compression dominated the slab down to the depth of 100 km, while down-dip tension occured at 100 to 300 km deep. In Region III the down-dip compression dominated the slab down to the depth of 100 km,down-diptensions dominated the slab from 100.to 300 km deep, while below this depth the earthquakes were dominated by the down-dip compression.

Abstrak :
ABSTRAK Metoda gaya berat secara cepat dapat digunakan dalam eksplorasi untuk mengetahui daerah jebakan baluan kontak yang terkaolinisasi ataupun cekungan tua yang diperkirakan mengandung mineral yang bernilai ekonomis. Untuk pemisahan anomali regional-sisa diterapkan metoda pencocokan permukaan ( surface fitting ) menggunakan polinomial non-ortogonal dalam koordinat " geografi " X dan Y yang dikenal sebagai Trend Surface Analysis. Penafsiran data gaya berat menggunakan pemodelan tiga dimensi metoda Talwani & Ewing dilakukan untuk mendapatkan model geometri bawah permukaan di daerah penelitian ( Pemali-Bangka ), dengan ditunjang oleh data geologi daerah tersebut sebagai data kontrol. Hasil pemodelan menggunakan metoda Talwani dan Ewing membuktikan aclanya struktur jebakan kontak antara granit dan metasedimen. Batuan kontak ini berbentuk topi ( kopula ) yang menutupi tonjolan granit. Batuan kontak ini secara geologi banyak mengandung timah.

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ABSTRACT The Gravity methods are used for preliminary in geophysical interpretation to delineate mineral deposit. The surface fitting method using non-orthogonal polynomial was applied for separation of the regional-residual anomaly in the geographical coordinate (){,Y) which is known as Trend Surface Analysis. The gravity data interpretation was used by three dimensional model of Talwani & Ewing ( 1960 ) to obtain the geometrical model of anomaly body under surface at the research area in Pemali-Bangka, this interpretation is supported by the geological map of the area as the reference. The result by this method showed that there is a structure between the granite and metasedimen. This structures form a cap covered the granite intrusion that geologically contain tin deposit. ;The Gravity methods are used for preliminary in geophysical interpretation to delineate mineral deposit.

Abstrak :
Telah dilakukan penelitian tentang karakterisasi reservoar dan batuan induk untuk mengetahui persebaran distribusi reservoar formasi Talang-Akar cekungan Sumatera Selatan. Penelitian ini berdasarkan integrasi data geofisika, geologi dan petrofisika. Tujuan penelitian ini untuk mengetahui karakteristik reservoir dan batuan induk Lapangan studi, membedakan reservoir dan batuan induk dalam satu formasi yaitu formasi Talang Akar, serta mengetahui persebaran net pay lapisan reservoir dan batuan induk. Metode yang digunakan adalah integrasi geofisika, geologi dan petrofisika, yang meliputi interpretasi data seismik menggunakan peta struktur waktu dan kedalaman, inversi seismik post-stack, kecepatan interval, interpretasi geologi meliputi analisa sturktur dan sesar, dan pengolahan data petrofisika dengan menginterpretasi data log sumuran yang menembus Formasi Talangakar yang mengandung hidrokarbon minyak dan gas. Berdasarkan interpretasi seismik, didapat penarikan 4 horison, yaitu Top Lapisan I, Top Lapisan D, Top Lapisan A dan Top Lapisan BRF, yang kemudian dilakukan pemetaan bawah permukaan pada lapisan A dan I untuk mengetahui perkembangan struktur di Daerah Penelitian. Berdasarkan interpretasi geologi, pemerangkapan di Daerah Penelitian berupa struktur antiklin berarah baratdaya-timurlaut yang dibatasi oleh patahan normal pada bagian baratdaya dan tenggara struktur Daerah Penelitian. Berdasarkan analisa petrofisika, reservoir yang utama pada lapangan penelitian, adalah lapisan A dengan kedalaman 1375 m dan ketebalan antara 2 ndash; 8.3 meter. Sedangkan dengan menggunakan data validasi yaitu menggunakan data side wall core sumur TMB-11, lapisan yang berpotensi sebagai batuan induk berkisar 1512 m yang equivalen dengan lapisan I yang memiliki nilai net-pay atau ketebalan batuan pasir yaitu 1,98 meter. Sehingga dapat dilakukan pembedaan daerah penelitian bahwa terdapat satu reservoir yang utama yaitu lapisan A dan batuan induk I pada formasi Talang Akar.

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Reservoir and source rock characterization has been performed to deliniate the reservoir distribution of Talang akar Formation South Sumatra Basin. This study is based on integrated geophysics, geology and petrophysical data. The aims of study is to determine the characteristics of the reservoir and source rock, to differentiate reservoir and source rock in same Talang Akar formation, to find out the distribution of net pay reservoir and source rock layers. The method of geophysical included seismic data interpretation using time and depth structures map, post stack inversion, interval velocity, geological interpretations included the analysis of structures and faults, and petrophysical processing is interpret data log wells that penetrating Talangakar formation containing hydrocarbons oil and gas. Based on seismic interpretation, obtained of the four horizons, those are Top Layer I, Top Layer D, Top Layer A and Top Layer BRF, which then perform subsurface mapping on Layer A and Layer I to determine the development of structures in the Regional Research. Based on the geological interpretation, trapping in the form of regional research is anticline structure on southwest northeast trending and bounded by normal faults on the southwest and southeast regional research structure. Based on petrophysical analysis, the main reservoir in the field of research, is a layer 1,375 m of depth and a thickness 2 to 8.3 meters. While using data validation that used side wall core data of the well TMB 11, the layer as a potential source rock ranging of depth from 1,512 m which is equivalent to the layer I that has a net pay thickness of sand 1.98 meters. It can distinguish the main research areas of reservoirs and rock layers of A and layer I in Talang Akar formation.

Abstrak :
ABSTRAK
We propose a new inverse problem formulation based on the hydrodynamics consideration of a gas/water fluid that results in planetary waves diagnostics. We analyze such a possibility beginning from a simplest version of geophysical hydrodynamics, written in the B plane model. The problem of diagnostics is solved approximately after expansion with respect to the transverse basis functions applying projecting to Rossby and Poincare waves in each transverse subspace that contains its superposition. The corresponding discrete version of the operators is built to be applied to the observation data.

Abstrak :
Tambang Bawah Tanah Kucing Liar adalah salah satu tambang prospek yang sedang dikembangkan oleh PT Freeport Indonesia. Berbagai kajian mengenai kondisi batuan di area Tambang Bawah Tanah Kucing Liar sedang dilakukan sebelum kegiatan penambangan dengan metode block caving dimulai. Penelitian ini bertujuan untuk mengetahui kondisi batuan di area Kucing Liar melalui metode klasifikasi massa batuan. Metode klasifikasi massa batuan yang digunakan ialah metode Rock Mass Rating (RMR) Bieniawski (1989) berdasarkan data geophysical borehole logging. Dari hasil pengolahan data pada empat lubang bor yang digunakan, pendekatan dengan metode geophysical borehole logging telah mampu mengidentifikasi dan mengkarakterisasi parameter RMR untuk setiap klasifikasi domain geologi. Dari hasil perhitungan dan analisis menunjukkan bahwa klasifikasi massa batuan (RMR) untuk setiap domain Formasi, Litologi, dan Alterasi tergolong ke dalam kelas baik (2) hingga sangat baik (1). Kondisi ini terindikasi akan berdampak pada proses block caving yang berpotensi menghasilkan blok-blok batuan berukuran besar sehingga mengakibatkan batuan tidak dapat runtuh dengan baik. ......The Kucing Liar Underground Mine is one of the prospect mines being developed by PT Freeport Indonesia. Various studies on the rock conditions in the Kucing Liar Underground Mine area are being conducted before mining activities with the block caving method begin. This study aims to determine the rock conditions in the Kucing Liar area through the rock mass classification method. The rock mass classification method used is the Rock Mass Rating (RMR) method of Bieniawski (1989) based on geophysical borehole logging data. From the results of data processing on the four borehole used, the geophysical borehole logging approach has been able to identify and characterize the RMR parameters for each geological domain classification. The calculation and analysis results show that the rock mass classification (RMR) for each Formation, Lithology, and Alteration domain is classified as good (2) to very good (1). This condition is indicated to have an impact on the block caving process which has the potential to produce large rock blocks, causing the rocks not being able to collapse properly.