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Mekanisme Gempa Vulkanik Gunung Talang Pasca Gempa Tektonik Mentawai Tahun 2007-2009, Sumatra Barat Kriswati, Estu; Pamitro, Y. E.; Basuki, A.
Indonesian Journal on Geoscience Vol 5, No 3 (2010)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (856.494 KB) | DOI: 10.17014/ijog.v5i3.104

Abstract

DOI: 10.17014/ijog.v5i3.104The Mentawai tectonic earthquake (magnitude 6.8 on the Richter Scale) on April 10, 2005 is assumed to trigger Talang volcanic activity that caused an eruption on April 12, 2005. Information on the source mechanism of volcanic earthquakes after the tectonic earthquake is expected to answer question of “Do tectonic earthquakes around the Talang Volcano trigger its volcanic activities?” Epicenter distribution of the volcanic earthquakes between 2007 and 2009 shows a southeast – northwest pattern with dextral strike-slip fault and normal fault mechanisms. The data show that earthquake activities at the Talang Volcano were dominated by local structure movements influenced by regional tectonic movements. Between 2007 and 2009, there were three process stages related to magnitude 6 or larger tectonic earthquakes around the Talang Volcano. First stage was a period before August 16, 2009. In this stage, volcanic fluids rose to the shallower chamber beneath the Talang Volcano. Second stage was a compressional stage and formation of a reverse fault influenced by Mentawai tectonic earthquake on August 16, 2009 and activation of a fault that intersects the Volcano. The third stage was a compresional stage and formation of a reverse fault influenced by Padang tectonic earthquake on September 30, 2009. In this stage, area fracturing was intensified, thereby the fracturing became more intensive. As the result, the accumulated volume and pressure of several tectonic earthquakes were released that caused an increase of eruption column soon after the tectonic earthquake.
Characteristic of Lokon Volcano Deformation of 2009 - 2011 Based on GPS Data Suhartaman, Suhartaman; Suparman, Y.; Abidin, H. Z.; Sinaga, Tumpal; Kriswati, Estu; Meilano, I.
Indonesian Journal on Geoscience Vol 7, No 4 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2717.865 KB) | DOI: 10.17014/ijog.v7i4.147

Abstract

DOI: 10.17014/ijog.v7i4.147Precursor of Lokon Volcano eruptions in 2011 is believed to begin since December 2007 which was marked by increasing number of volcanic earthquakes and gas emission. To support this information, deformation method is used primarily to determine deformation characteristics of Lokon volcanic activity in the period of 2009-2011. The period of analysis is adapted to the presence of GPS data. Displacement rate of Lokon GPS observation points in the period of 2009 - 2011 ranged from 1.1 to 7 cm a year. Strain patterns that occur in the areas are compression surrounding Tompaluan crater and extension in the eastern slope. Location of the pressure source for August 2009 - March 2011 measurement was at a depth of 1800 m beneath Tompaluan crater. Deformation in the Lokon Volcano is characteristized by the compression zone in the summit and crater area caused by magma activity raised into the surface from a shallow magma source which is accompanied by a high release of volcanic gases. Accumulated pressure release and deformation rate as measured in the Lokon Volcano remain low.
Pengaruh Gempabumi Tektonik Terhadap Aktivitas G. Gede Hidayati, Sri; Sulaeman, Cecep; Supartoyo, Supartoyo; Kriswati, Estu
Jurnal Geologi dan Sumberdaya Mineral Vol 19, No 4 (2018): Jurnal Geologi dan Sumberdaya Mineral
Publisher : Pusat Survei Geologi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (320.618 KB)

Abstract

In addition to home for seven active volcanoes, West Java, is also having high tectonic activity, owing to its close distance from subduction zone and crustal fault. The Cimandiri Fault extends about 100 km from southwest to the northeast ward through Sukabumi area. Gede Volcano with high seismic activity is sitting 20 km north of Cimandiri Fault. Shallow earthquakes often occur around Gede volcano and their sources are fairly close to the Cimandiri valley. Feltearthquakes occurred in 2007, 2010, 2012 and 2014,where the source supposed to be around Cimandiri valley,were followed by volcano-tectonic (VT) earthquake swarms in Gede Volcano. These swarms probably indicate that there is a linkage between tectonic and Gede volcano activities. However, the swarms were followed by less significant changes in volcanic activity. GPS data during measurement period of 2006-2015 show the existence of a fault with main stress in the northwest-southeast direction. The mechanism of the Cimandiri Fault is reverse fault with sinistral slip component and sinistral strike slip fault, while the swarm of VT earthquakes in Gede Volcano is dominated by reverse and normal faults. Tectonic earthquakes may trigger nearby volcanic eruption; it depends on the state of magma of the volcano and the magnitude of the earthquake.Keyword: Tectonic, Cimandiri fault, VT earthquake, Gede Volcano.
Mekanisme Gempa Vulkanik Gunung Talang Pasca Gempa Tektonik Mentawai Tahun 2007-2009, Sumatra Barat Kriswati, Estu; Pamitro, Y. E.; Basuki, A.
Indonesian Journal on Geoscience Vol 5, No 3 (2010)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (856.494 KB) | DOI: 10.17014/ijog.5.3.209-218

Abstract

DOI: 10.17014/ijog.v5i3.104The Mentawai tectonic earthquake (magnitude 6.8 on the Richter Scale) on April 10, 2005 is assumed to trigger Talang volcanic activity that caused an eruption on April 12, 2005. Information on the source mechanism of volcanic earthquakes after the tectonic earthquake is expected to answer question of “Do tectonic earthquakes around the Talang Volcano trigger its volcanic activities?” Epicenter distribution of the volcanic earthquakes between 2007 and 2009 shows a southeast – northwest pattern with dextral strike-slip fault and normal fault mechanisms. The data show that earthquake activities at the Talang Volcano were dominated by local structure movements influenced by regional tectonic movements. Between 2007 and 2009, there were three process stages related to magnitude 6 or larger tectonic earthquakes around the Talang Volcano. First stage was a period before August 16, 2009. In this stage, volcanic fluids rose to the shallower chamber beneath the Talang Volcano. Second stage was a compressional stage and formation of a reverse fault influenced by Mentawai tectonic earthquake on August 16, 2009 and activation of a fault that intersects the Volcano. The third stage was a compresional stage and formation of a reverse fault influenced by Padang tectonic earthquake on September 30, 2009. In this stage, area fracturing was intensified, thereby the fracturing became more intensive. As the result, the accumulated volume and pressure of several tectonic earthquakes were released that caused an increase of eruption column soon after the tectonic earthquake.
Characteristic of Lokon Volcano Deformation of 2009 - 2011 Based on GPS Data Kriswati, Estu; Meilano, I.; Suhartaman, Suhartaman; Suparman, Y.; Abidin, H. Z.; Sinaga, Tumpal
Indonesian Journal on Geoscience Vol 7, No 4 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2717.865 KB) | DOI: 10.17014/ijog.7.4.199-209

Abstract

DOI: 10.17014/ijog.v7i4.147Precursor of Lokon Volcano eruptions in 2011 is believed to begin since December 2007 which was marked by increasing number of volcanic earthquakes and gas emission. To support this information, deformation method is used primarily to determine deformation characteristics of Lokon volcanic activity in the period of 2009-2011. The period of analysis is adapted to the presence of GPS data. Displacement rate of Lokon GPS observation points in the period of 2009 - 2011 ranged from 1.1 to 7 cm a year. Strain patterns that occur in the areas are compression surrounding Tompaluan crater and extension in the eastern slope. Location of the pressure source for August 2009 - March 2011 measurement was at a depth of 1800 m beneath Tompaluan crater. Deformation in the Lokon Volcano is characteristized by the compression zone in the summit and crater area caused by magma activity raised into the surface from a shallow magma source which is accompanied by a high release of volcanic gases. Accumulated pressure release and deformation rate as measured in the Lokon Volcano remain low.
Lava Discharge Rate of Sinabung Volcano Obtained from Modis Hot Spot Data Kriswati, Estu; Solikhin, Akhmad
Indonesian Journal on Geoscience Vol 7, No 3 (2020)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (10408.723 KB) | DOI: 10.17014/ijog.7.3.241-252

Abstract

DOI:10.17014/ijog.7.3.241-252To find out the long term data of Sinabung magma discharge rate and how long a series of eruption will be ended, time series of the volume of magma discharge is required. The dominant eruption product is pyroclastic flow that begins with the growth of the lava dome, so it is important to determine the volume of the lava dome over time. The method of determining the volume of magma issued is carried out by using hotspot data to resolve the problem of prevented visual observations and ground measurements. The heat and volume flux data expressed within a long period for a better view of variations in the Sinabung volcanic activity are based on thermal satellite data. Related lava dome volume and seismic data are also displayed to be compared with the heat and volume flux data. The numbers of thermally anomalous pixels and sum of radiance for all detected pixels at Sinabung during an overpass in the period of 2014 to 2018 have a downward trend. The discharge rates in the period of January 2014 to April 2015, Mei 2015 to March 2016, April 2016 to March 2017, and June 2017 to February 2018 are 0.86 m3/sec, 0.59 m3/sec, 0.36 m3/sec, and 0.25 m3/sec, respectively. Assuming no new intrusion or deformation rate changes, the lava discharge will be in the lowest rate in the early 2020s.
Mekanisme Gempa Vulkanik Gunung Talang Pasca Gempa Tektonik Mentawai Tahun 2007-2009, Sumatra Barat Kriswati, Estu; Pamitro, Y. E.; Basuki, A.
Indonesian Journal on Geoscience Vol 5, No 3 (2010)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.5.3.209-218

Abstract

DOI: 10.17014/ijog.v5i3.104The Mentawai tectonic earthquake (magnitude 6.8 on the Richter Scale) on April 10, 2005 is assumed to trigger Talang volcanic activity that caused an eruption on April 12, 2005. Information on the source mechanism of volcanic earthquakes after the tectonic earthquake is expected to answer question of “Do tectonic earthquakes around the Talang Volcano trigger its volcanic activities?” Epicenter distribution of the volcanic earthquakes between 2007 and 2009 shows a southeast – northwest pattern with dextral strike-slip fault and normal fault mechanisms. The data show that earthquake activities at the Talang Volcano were dominated by local structure movements influenced by regional tectonic movements. Between 2007 and 2009, there were three process stages related to magnitude 6 or larger tectonic earthquakes around the Talang Volcano. First stage was a period before August 16, 2009. In this stage, volcanic fluids rose to the shallower chamber beneath the Talang Volcano. Second stage was a compressional stage and formation of a reverse fault influenced by Mentawai tectonic earthquake on August 16, 2009 and activation of a fault that intersects the Volcano. The third stage was a compresional stage and formation of a reverse fault influenced by Padang tectonic earthquake on September 30, 2009. In this stage, area fracturing was intensified, thereby the fracturing became more intensive. As the result, the accumulated volume and pressure of several tectonic earthquakes were released that caused an increase of eruption column soon after the tectonic earthquake.
Characteristic of Lokon Volcano Deformation of 2009 - 2011 Based on GPS Data Kriswati, Estu; Meilano, I.; Suhartaman, Suhartaman; Suparman, Y.; Abidin, H. Z.; Sinaga, Tumpal
Indonesian Journal on Geoscience Vol 7, No 4 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.7.4.199-209

Abstract

DOI: 10.17014/ijog.v7i4.147Precursor of Lokon Volcano eruptions in 2011 is believed to begin since December 2007 which was marked by increasing number of volcanic earthquakes and gas emission. To support this information, deformation method is used primarily to determine deformation characteristics of Lokon volcanic activity in the period of 2009-2011. The period of analysis is adapted to the presence of GPS data. Displacement rate of Lokon GPS observation points in the period of 2009 - 2011 ranged from 1.1 to 7 cm a year. Strain patterns that occur in the areas are compression surrounding Tompaluan crater and extension in the eastern slope. Location of the pressure source for August 2009 - March 2011 measurement was at a depth of 1800 m beneath Tompaluan crater. Deformation in the Lokon Volcano is characteristized by the compression zone in the summit and crater area caused by magma activity raised into the surface from a shallow magma source which is accompanied by a high release of volcanic gases. Accumulated pressure release and deformation rate as measured in the Lokon Volcano remain low.
Lava Discharge Rate of Sinabung Volcano Obtained from Modis Hot Spot Data Kriswati, Estu; Solikhin, Akhmad
Indonesian Journal on Geoscience Vol 7, No 3 (2020)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.7.3.241-252

Abstract

DOI:10.17014/ijog.7.3.241-252To find out the long term data of Sinabung magma discharge rate and how long a series of eruption will be ended, time series of the volume of magma discharge is required. The dominant eruption product is pyroclastic flow that begins with the growth of the lava dome, so it is important to determine the volume of the lava dome over time. The method of determining the volume of magma issued is carried out by using hotspot data to resolve the problem of prevented visual observations and ground measurements. The heat and volume flux data expressed within a long period for a better view of variations in the Sinabung volcanic activity are based on thermal satellite data. Related lava dome volume and seismic data are also displayed to be compared with the heat and volume flux data. The numbers of thermally anomalous pixels and sum of radiance for all detected pixels at Sinabung during an overpass in the period of 2014 to 2018 have a downward trend. The discharge rates in the period of January 2014 to April 2015, Mei 2015 to March 2016, April 2016 to March 2017, and June 2017 to February 2018 are 0.86 m3/sec, 0.59 m3/sec, 0.36 m3/sec, and 0.25 m3/sec, respectively. Assuming no new intrusion or deformation rate changes, the lava discharge will be in the lowest rate in the early 2020s.
ANALISIS DEFORMASI GUNUNG API BATUR BERDASARKAN DATA PENGAMATAN GPS BERKALA TAHUN 2008, 2009, 2013, DAN 2015 DEFORMATION ANALYSIS OF BATUR VOLCANO BASED ON PERIODIC GPS OBSERVATIONS DATA IN 2008, 2009, 2013, AND 2015 Achmad Faris; Estu Kriswati; Irwan Meilano; Dina Anggreni Sarsito
Jurnal Lingkungan dan Bencana Geologi Vol 9, No 1 (2018)
Publisher : Badan Geologi

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2132.048 KB) | DOI: 10.34126/jlbg.v9i1.194

Abstract

ABSTRAKGunung Batur yang terletak di Kabupaten Bangli, Bali, terakhir meletus pada tahun 2000. Pada 2009 terjadi peningkatan aktivitas vulkanis di Gunug Batur walaupun tidak terjadi letusan. Penelitian ini bertujuan untuk mengetahui pola deformasi pada Gunung Batur serta keterkaitannya dengan peningkatan vulkanis pada tahun 2009. Analisis didasarkan pada pola vektor pergeseran dan pola regangan masing-masing titik pengamatan GPS berkala pada area Gunung Batur tahun 2008, 2009, 2013, dan 2015. Berdasarkan pengamatan GPS Oktober 2008-November 2009 pola deformasi menunjukkan adanya inflasi dengan pola vektor pergeseran titik pengamatan GPS dominan ke arah luar dari Gunung Batur, selain itu pola regangan memperlihatkan bahwa pada area bagian utara dan timurlaut Gunung Batur dominan terjadi ekstensi. Pada pengamatan GPS untuk periode November 2009-Februari 2013 pola deformasi menunjukkan adanya deflasi pada Gunung Batur dengan pola vektor pergeseran titik pengamatan GPS berarah menuju Gunung Batur dan pola regangan memperlihatkan bahwa pada area Gunung Batur terjadi kompresi. Kata Kunci: Gunung Batur, deflasi, deformasi, pergeseran, GPS, inflasi, regangan. ABSTRACTBatur volcano located in Bangli, Bali, last erupted in 2000. Increased in the volcanic activity occurred in 2009 but did not followed by eruption. This study aims to determine ground deformation pattern in Batur volcano and its association with the increased in volcanic activity in 2009 based on the pattern of displacement vector and strain using 2008-2015 campaign GPS data. During period of October 2008-November 2009, Batur Volcano experience inflation and strain pattern shows that the area of the north and northeast of Batur Volcano experienced extension. During November 2009-February 2013, Batur Volcano experienced deflation with GPS displacement directed towards Batur Volcano and a strain pattern of compression around Batur Volcano. Keywords: Batur Volcano, deflation, deformation, displacement, GPS, inflation, strain.