M Maruf Mukti

Basin Dynamis Group - BRIN

The study location is in the southernmost region of Simeulue Island near the Indo-Australian subduction margin. The deformation and geodynamic evolution around the island have been studied through some geophysical and geological studies. However, information regarding crustal seismic anisotropy around this region is less investigated, which may be...

Lake Toba, North Sumatra, Indonesia, is one of the biggest calderas in the world. The area is also prone to earthquake damage because of the tectonic activity due to its location in the subduction zone of Indo-Australian and Eurasian Plates. In recent years, Lake Toba has become one of the most attractive tourist destinations in Indonesia. Hence, t...

In recent years, dozen low-intensity earthquakes occurred in southern Garut, West Java Indonesia; two of them were reported destructive. However, those shallow earthquake clusters are hardly associated with well-known active faults in the area. Hence, we conducted 3D gravity combined with 2D magnetotellurics (MT) inversions to study the subsurface....

The enigmatic genesis of Sulawesi Island remains a debate among earth scientists up to the present day. The Northern Arm of Sulawesi is designated as a volcanic province, while the Eastern Arm is identified as an ophiolite zone along with several micro continental fragments. However, the tectonic relationship in the marine area between these two ar...

Toba Lake is one of the largest caldera lakes in the world, formed by an enormous eruption about 74,000 years ago. The emergence of hot spring manifestations around Lake Toba is closely related to volcanic activity, which is also controlled by regional geological structures. There are two areas in Lake Toba: Simbolon and Pusuk Buhit, with several g...

Based on structural deformation analysis in the oblique Sumatra subduction system, we review uplift mechanisms of the forearc high and formation of the forearc basin. The development of the forearc high has been attributed to the flexural uplift, basin inversion, uplift of older accretion wedge, and backthrust in the landward margin of the accretio...

The Sumatran offshore region is known as an active seismogenic zone. Consequently, there were many records of great events that caused a big catastrophe, such as the 2004 Sumatra-Andaman earthquake. In order to investigate the geometry and nature of the earthquake ruptures and structures, we utilize the bathymetry and Multi-Channel Seismic (MCS) pr...

The growth of forearc basins in an oblique subduction system has been proposed to have related to strike-slip faulting due to strain partitioning. We reviewed several models of the primary controls on the evolution of the forearc basin in the western Sunda subduction zone: formation of the sliver plate, the occurrence of continental backstop, devel...

Most earthquake studies focus mainly on offshore subduction zones that often produce high-magnitude earthquakes. However, onshore active fault earthquakes also common to cause significant devastation, due to their proximity to human activity and their relatively shallow depth. Most of active faults in Java show a west-east (W-E) trending direction....

We present a morphotectonic study of the offshore northern Sumatra fore-arc high and fore-arc basin and an evolutionary model of the area based on high-resolution marine geophysical datasets. We show that the landward slope of the fore-arc high and the western edge of the Aceh fore-arc basin host a set of deeply-rooted, seaward-dipping backthrusts:...

An ENE‐WSW‐trending localized basalt‐diabase outcrop along the SE margin of Luk Ulo Mélange Complex has been suggested as intrusive rocks cut through the Paleogene Totogan and Karangsambung formations. However, the absolute dating of the volcanics is older than the inferred relative age of the sedimentary formations, hence the in‐situ intrusion the...

We analysed receiver functions from teleseismic events recorded at 11 broadband seismometers in the western part of Java Island, Indonesia. The stations are mostly located at three main geological environment including Northwest Java Basin, Bogor Zone, and Southern Mountains Arc. A total of about 341 receiver functions were computed using iterative...

This paper presents a review of several published seismic reflection and seismicity data and analyzes of high-resolution bathymetry data to revise the exact location and reveal detail characteristics of a strike-slip fault zone that formed the southernmost segment of the Sumatran Fault (SF). Previous works interpreted this fault segment as a horst...

We present an interpretation of newly acquired audio-magnetotelluric data to reveal the subsurface geometry of Cimandiri Fault Zone, one of the major active faults in the western part of Java. The line section is 25 km long in a nearly north–south direction across the axes of CFZ with 24 stations of 750–1200 m spacing intervals. The 2D AMT inversio...

The area from Andaman to northern Sumatran margin is a region where major faults collided that complicates the structural configuration. The origin of structures in the boundary between the accretionary wedge and forearc basin in the northwesternmost segment of the Sunda margin has been a subject of debates. This article reviews several published w...

Re-examination of published seismic data in the southeasternmost segment of the active Sumatra Fault zone (SFZ) reveals the characteristics of structural style and depositional history of Semangko pull apart basin (SPB). The SPB have been developed as a transtensional pull apart basin resulted from stepping over of the Semangko to Ujung Kulon segme...

The Luk Ulo Mélange Complex (LUMC) is composed of tectonic slices of rocks that surrounded by scaly clay matrix. These rocks consist of serpentinite, gabbro, diabase, and basalt, eclogite, blueschist, amphibolite, schist, gneiss, phylite and slate, granite, chert, red limestone, claystone and sandstone. The LUMC was formed since Paleocene to Eocene...

The origin of mélange complexes has been the subject of speculation of geologists since their first recognition in the 1900s. Type of mélange complex plays a role in the tectonic reconstruction of active margin. Several locations in the southern Sundaland margin expose remnant of Mesozoic subduction zone as basement and sedimentary rocks in mélange...

Earthquake Geology of Indonesia Geologi Gempa Indonesia

The characteristic of Cimandiri Fault Zone has not been completely defined despite plenty of studies had already been accomplished. Therefore, an audio-magnetotelluric modeling was carried out. An audiomagnetotelluric survey was conducted at two parallel lines (N166oE) that intersected Cimandiri Fault Zone in Cibeber area, Cianjur. The distance bet...

Structural evolution of the Semangko pull apart basin in the Sunda Strait is analyzed based on palinspastic reconstructions of re-interpreted seismic reflection data to understand the timing and kinematics of structures in such basin. We use more than seven multichannel seismic reflection data combined with swath bathymetry and seismicity data avai...

Structural evolution of the Semangko pull apart basin in the Sunda Strait is analyzed based on palinspastic reconstructions of re-interpreted seismic reflection data to understand the timing and kinematics of structures in such basin. We use more than seven multichannel seismic reflection data combined with swath bathymetry and seismicity data avai...

Structural evolution of the Semangko pull apart basin in the Sunda Strait is analyzed based on palinspastic reconstructions of re-interpreted seismic reflection data to understand the timing and kinematics of structures in such basin. We use more than seven multichannel seismic reflection data combined with swath bathymetry and seismicity data avai...

The microstructures of turbiditic and hemipelagic muds and mudstones were investigated using a scanning electron microscope to determine whether there are microstructural features that can differentiate turbiditic from hemipelagic sedimentary processes. Both types of muddy deposits are, in general, characterized by randomly-oriented clay particles....

Seven deep seismic reflection profiles cover the 3000 km-long subduction system from Andaman to Southern Sumatra, including zones that ruptured in 2004, 2007, and 2010. We find that (1) the frontal zone is characterized by a series of thrusts bounding folded blocks of sediments with preserved layering, showing a northward transition from dominantly...

We present the interpretation of newly acquired high-quality industry-standard deep seismic reflection and swath bathymetry data to provide insight into the structural style and evolution of the Mentawai Fault Zone (MFZ). The MFZ lies along the boundary between the accretionary wedge and the proposed continental backstop. This zone exhibits arcuate...

The Mentawai segment of the Sumatra subduction zone is locked and likely to produce a large earthquake in the near future. A part of this locked zone ruptured on 12 September 2007 producing twin earthquakes of Mw = 8.5 and 7.9. Recently, a third earthquake of Mw = 7.8 occurred on the 25th October 2010, SW of Pagai Island, Sumatra. The earthquake ge...

The subduction of large topographic features such as seamounts has been linked to plate locking, earthquake generation and segmentation, as well as crustal erosion at subduction zones. However, the role of subducted features in the generation of megathrust earthquakes has been difficult to discern because traditional imaging techniques are limited...

This evaluation is made following the unsuccessful of six exploration wells drilling in the deepwater of Makassar Strait. The geological factor of this unsuccessful result is in interpreting the presence of reservoir and source rock, in particular: misinterpretation of age of the carbonate reservoirs in the seismic correlation and less attention on...

The Sumatra subduction zone is a classical example of oblique subduction where the slip is partitioned between an orthogonal component along the megathrust and an arc parallel component along the Sumatran fault. It was previously suggested that the part of the arc parallel motion is accommodated along the Mentawai strike-slip fault. Using high-qual...

Subducted bathymetric highs and lows provide important controls on the locking mechanism, earthquake generation and segmentation, and on crustal erosion at subduction zones. However, until now, it has been only possible to image subducted features down ~10 km depth due to a combination of poor penetration of seismic energy, reverberation of seismic...

We report the first discovery of outcrop-scale, fine-grained sediment waves in the left-side muddy overbank deposits relative to the down-current direction of the adjacent channel deposits in the lower Halang Formation turbidite system in a late Miocene back-arc basin, West Java. The present outcrop examples are characterized by an average waveleng...

Penelitian lapangan dan analisa di laboratorium telah dilakukan untuk menentukan sebaran fasies karbonat dan interpretasi lingkungan pengendapan serta morfologi platform dari batugamping Tersier Formasi Wonosari di sebelah timur Pacitan. Sampel batuan diklasifikasikan berdasarkan klasifikasi Jordan (1985) yang kemudian diinterpretasikan lingkungan...