cover
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota bandar lampung,
Lampung
INDONESIA
Jurnal Geofisika Eksplorasi
Published by Universitas Lampung
ISSN : 23561599     EISSN : -     DOI : -
Core Subject : Science,
Jurnal Geofisika Eksplorasi adalah jurnal yang diterbitkan oleh Jurusan Teknik Geofisika Fakultas Teknik Universitas Lampung. Jurnal ini diperuntukkan sebagai sarana untuk publikasi hasil penelitian, artikel review dari peneliti-peneliti di bidang Geofisika secara luas mulai dari topik-topik teoritik dan fundamental sampai dengan topik-topik terapandi berbagai bidang. Jurnal ini terbit tiga kali dalam setahun (Maret, Juli dan November), Volume pertama terbit pada tahun 2013 dengan nama Jurnal Geofisika Eksplorasi (JGE).
Arjuna Subject : -
Articles 6 Documents
Search results for , issue " Vol 1, No 02 (2013)" : 6 Documents clear
STUDI PENCITRAAN STRUKTUR BAWAH PERMUKAAN BUMI MENGGUNAKAN PEMODELAN CONSTRAINED VELOCITY INVERSION DAN GRID BASED TOMOGRAPHY PADA LINTASAN GMR165 DI DAERAH TELUK CENDRAWASIH Rizka, Gamal Muhammad
Jurnal Geofisika Eksplorasi Vol 1, No 02 (2013)
Publisher : Jurnal Geofisika Eksplorasi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (759.015 KB)

Abstract

  Prestack Depth Migration (PSDM) method has been applied to image the subsurface at Line GMR165 in Cendrawasih Bay. Imaging   and   positioning   is   the  most  important   issue   in seismic   data   processing.   In   the complex area case with lateral variation velocity , PSDM has more benefit than PSTM . It cause  the   ability   of   PSDM   method   that   can   focus just   for  one   reflector   when lateral velocity change.  In this study used constrained velocity inversion modelling method. This method is designed to make an initial interval velocity model for PSDM and updated in grid based tomography to got the best velocity so that the result had  continuous PSDM reflector with flat gather. That interval velocity applied to PSDM to get seismic image section and compared with PSTM (prestack time migration) seismic section based on it’s image and velocity model analysis. Seismic section of PSDM shows a significant image enhancement. It is able to assure the reflection pattern at the horizons with strong lateral velocity variations and makes image resolution more coherence than seismic section of PSTM. This study is very valuable to build exploration concept and development area, especially in a complex structure with strong lateral velocity variations.Keywords: Pre Stack Depth Migration, Constarined Velocity Inversion, Grid Based Tomography.  
ANALISIS KARAKTERISTIK DAN KLASIFIKASI GEMPA PADA GUNUNG LOKON BERDASARKAN REKAMAN DATA SEISMOGRAM APRIL – MEI 2012 Putri, Leovina Prinanda
Jurnal Geofisika Eksplorasi Vol 1, No 02 (2013)
Publisher : Jurnal Geofisika Eksplorasi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1289.363 KB)

Abstract

This research has been carried out aiming to classify earthquakes at Lokon Volcano and analyze the character of the earthquakes to determine the mechanism of the eruption of Lokon Volcano is based on the data recorded seismograms April to May 2012. The stages in analyzing the characteristics of the earthquake is the waveform analysis and spectral analysis . On waveform analysis aims to determine the P wave comes time ( Tp ) and S waves ( Ts ) and the duration of the earthquake . While spectral analysis aimed to determine the frequency of these earthquakes . The second stage of the obtained classification of volcanic earthquakes in the earthquakes, shallow volcanic earthquakes, earthquake monochromatic, and tectonic earthquake. Shallow volcanic earthquakes located at depths of 0.5 to -1.5 km , duration range from 3 to 16 seconds with a frequency range from 4 Hz to 18 Hz . Volcanic earthquakes located at depths -6 km to -1,duration range from 6 to 20 seconds with a frequency range from 6 Hz to 13 Hz . Earthquake discovered long period is two monochromatic low frequency earthquakes at depths of up to -1.5 -2 km which has two peaks in each of the station frequency is the frequency of the dominant and sub - dominant . Dominant frequency of the seismic monochromatic range 2.88 Hz to 4.88 Hz and sub -dominant frequency range from 5.04 Hz to 8.7 Hz . Duration of tectonic earthquakes about 50 until 470 seconds with a frequency range from 1 to 6 Hz. Volcanic earthquakes and monochromatic associated with normal faulting .Increased seismic activity indicates impending eruption.Keywords : hypocenter , classification earthquake , monochromatic earthquake , eruption mechanisms.
PENDEKATAN INVERSI 1D UNTUK MENGURANGI EFEK GALVANIC PADA MODEL 2D MAGNETOTELLURIK DAERAH PANASBUMI DANAU RANAU Wibowo, Muhammad Gunadi Arif
Jurnal Geofisika Eksplorasi Vol 1, No 02 (2013)
Publisher : Jurnal Geofisika Eksplorasi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (647.586 KB)

Abstract

Metode magnetotelurik  adalah metode sounding elektromagnetik  untuk mengetahui struktur  tahanan jenis bawah permukaan dengan cara melakukan pengukuran pasif komponen medan listrik dan medan magnet alam  yang berubah terhadap waktu. Data MT tidak begitu  stabil  pada lapisan dangkal karena perbedaan topografi yang  mencolok yang disebut juga efek  galvanik  (distorsi galvanic). Untuk mengatasi data yang mengalami  shift tersebut dilakukanlah koreksi statik dengan menggunakan data TDEM. Dari informasi yang penulis dapat dari pihak Pusat Sumber Daya Geologi (PSDG), pada saat melakukan pengukuran di daerah Danau Ranau tidak menggunakan TDEM. Sehingga untuk menginterpretasikan titik-titik tersebut agar pemodelan sesuai dengan karakteristik sistem panasbumi yang diinginkan, maka penulis menggunakan pendekatan  hasil inversi 1D untuk menghilangkan efek  galvanik.  Daerah  impermeable (Claycap)  ditunjukkan oleh lapisan dengan nilai resistivitas ≤ 10 Ohm.m dengan ketebalan 700-1000 meter.  Kata kunci : Magnetotellurik, Efek galvanik, Inversi 1D, Resistivitas, Clay Cap
PENERAPAN KOREKSI STATIK TIME DOMAIN ELEKTROMAGNETIK (TDEM) PADA DATA MAGNETOTELLURIK (MT) UNTUK PEMODELAN RESISTIVITAS LAPANGAN PANAS BUMI “SS” Hardini, Putri
Jurnal Geofisika Eksplorasi Vol 1, No 02 (2013)
Publisher : Jurnal Geofisika Eksplorasi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (446.137 KB)

Abstract

Metode magnetotellurik (MT) merupakan metode elektromagnetik pasif yang memiliki jangkauan kedalaman yang lebih dalam dari metode geofisika lainnya. Hasil pengukuran magnetotellurik mengalami pergeseran statik akibat perbedaan topografi dan  heterogenitas lapisan permukaan, sehingga perlu dilakukan koreksi statik  Time Domain Elektromagnetik (TDEM). TDEM merupakan metode elektromagnetik aktif yang akurat untuk lapisan dangkal. Hasil pengolahan  koreksi statik pada semua lintasan daerah penelitian memiliki persebaran nilai resistivitas yang lebih akurat. Perkiraan lapisan penudung (claycap)  terlihat jelas pada lintasan ke-3 disekitar titik MT-19 dan MT-18 dengan nilai resistivitas < 10 ohm.m dan pada kedalaman 1000 meter msl.   Kata kunci: Magnetotellurik, TDEM, Claycap, Resistivitas.  
ANALISIS KARAKTERISTIK PANASBUMI DAERAH OUTFLOW GUNUNG ARJUNO-WELIRANG BERDASARKAN DATA GEOLOGI, GEOKIMIA, DAN GEOFISIKA (3G) Nidya, Ferra
Jurnal Geofisika Eksplorasi Vol 1, No 02 (2013)
Publisher : Jurnal Geofisika Eksplorasi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1799.507 KB)

Abstract

The research has been done  to analyzed characteristics of geothermal outflow at Mt.  Arjuno-Welirang  area,  based on geology,  geochemistry,  and  geophysics  data. Geochemistry data is used to determine type of fluid, temperature of reservoir, and framer of reservoir rocks. Geochemistry data  in outflow area produces bicarbonate water (HCO3) with the temperature of reservoir  in  this area about 145°C  to 175°C and  the  framer of  reservoir rock  is  basaltics. Analysis  of characteristics  geothermal system  components  (caprock  and reservoir)  based  on  physical properties  i.e. resistivity and density.   Resistivity value is resulted  from 2D magnetotellurics model and density value is resulted from 3D gravity model. From these results,  impermeable  (caprock) area  have a resistivity value about ≤ 10 Ohm.m with curve pattern in which side is thicker and density values is between 1,49 gr/cm3 and 2,4 gr/cm3 with distribution patterns  from west to east and the depth of  top  layer  from caprock   is  about  500 to 1000  m,  and type of  material  is  secondary  clay  mineral  and controlled  by  Fault Puncung.   For the  permeable  (reservoir)  in this  area  have a resistivity values at between 10 and 60 Ohm.m and density value is between 2,4 gr/cm3 and 2,67 gr/cm3 with  the depth about ≥1,5 km and type of material rock  is andesit-basaltic  lava  that produce of old lava bodies Mt.Arjuno-Welirang complex that spread out at west to south which earlier Kuarter age.  Key words: Type of Fluid, Temperature, Reservoir Rock, Resistivity and Density Value.
STUDI GELOMBANG SEISMIK GEMPA VULKANIK GUNUNG SINABUNG UNTUK MENENTUKAN KARAKTERISTIK MEKANISME VULKANIK Julian, Rianza
Jurnal Geofisika Eksplorasi Vol 1, No 02 (2013)
Publisher : Jurnal Geofisika Eksplorasi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (860.861 KB)

Abstract

Mount Sinabung is a stratovolcano  mount  located in Karo, North Sumatra. Geographically located between 3o 10’ North Latitude and 98o 23,5’ East Longitude. This type of explosive volcanic eruptions.  Lava flowing from the stratovolcano is usually cool and harden before spreading far due to high viscosity.  Magma forming this lava  and acidic contain medium to high levels of silica. To observe volcanic earthquakes at Mount Sinabung is used 4 permanent stations are Sukanalu station (SKN), Laukawar (KWR), Sukameriah (SKM), and Mardingding (MRD).  Research has been conducted using primary data of volcanic earthquakes Sinabung in 2011 till June 2012. Based on the results of the spread of volcanic earthquake hypocenter obtained, previously has made the process of picking and determining the value to, tp  with error <0.2.  Results hypocenter distribution of volcanic earthquakes at Mount Sinabung is as much as about 500 volcanic earthquakes, and its earthquakes are concentrated at a depth of 0 to 6 km  asl. Mechanisms of volcanic magma chamber at Mount Sinabung is at a depth of about 12 km above sea level, is the crack area (low frequency) and the area around the magma chamber (high frequency). Results of the average speed of P waves from the source to the receiver by a travel time curve is at 3.33 km/s. The dominant frequency of volcanic earthquakes Sinabung frequency value at station SKN smallest to largest on the station SKM is 0.28 Hz to 2.18 Hz.  Keywords :   Stratovolcano, Volcanic Earthquakes, Stations, Hypocenter, Magma Chamber, Travel Time, Frequency  

Page 1 of 1 | Total Record : 6