scholarly journals Comparison Study of Crustal Structure in Aceh Region based on Volcanic Arc System using Receiver Function Method

2021 ◽  
Vol 2110 (1) ◽  
pp. 012003
Author(s):  
R I Mahardiana ◽  
P Ariyanto ◽  
B Pranata ◽  
B S Prayitno
Keyword(s):  
Crustal Structure ◽  
Receiver Function ◽  
Velocity Model ◽  
Moho Depth ◽  
Comparison Study ◽  
Forward Modelling ◽  
Backarc Basin ◽  
Volcanic Arc ◽  
S Waves ◽  
Receiver Function Method

Abstract Aceh region has a very complex crustal structure from the forearc ridge to the backarc basin. This study aims to determine the velocity model of P and S waves and the depth of Moho discontinuity. This research was conducted using teleseismic earthquake data (30°-90° from the station) with M>6 from four seismic stations belonging to the BMKG in Aceh region. The stations are qualified based on the volcanic arc system zone. Furthermore, the velocity model determined by result of forward modelling, while the depth of the Moho layer estimated by migrated receiver function from time domain to the depth domain. At station SNSI that represented the forearc ridge zone, the depth of Moho is ±28 km, at station TPTI represent the forearc basin is ±16 km, while at zone with higher topography, namely volcanic arc zone represented by station KCSI, the Moho depth was identified at ±38 km, and the backarc basin represented by station LASI with ±40 km depth of Moho. This variation occurs because the composition of the earth’s layers below the station is diverse also different topography for each station.

Sediment Thickness and Moho Depth Beneath Western Indonesian Region From Teleseismic Receiver Function

2021 ◽  
Author(s):  
Syaiful Bahri ◽  
Wiwit Suryanto ◽  
Drajat Ngadmanto
Keyword(s):  
Shear Wave ◽  
Shear Wave Velocity ◽  
Receiver Function ◽  
Velocity Model ◽  
Moho Depth ◽  
Sediment Layer ◽  
The North ◽  
East Kalimantan ◽  
Crust Layer ◽  
Teleseismic Receiver Function

Abstract The Earth's crust layer and sediment in Western Indonesia has been studied using the inversion of teleseismic receiver function from BMKG’s seismic network. Earthquake events were analyzed in this study with a moment magnitude greater than 6.0 with epicentral distances of 30° to 90°. A total of 60 earthquake events were observed and recorded by 91 stations around the study area. Furthermore, an inversion process was carried out using the initial velocity model from the modification of the AK135f velocity model to obtain the shear wave velocity structure below each stations. The velocity model from the azimuthally stacked vertical receiver function showed that the sediment layer had a relatively medium shear wave velocity value with an average of 2.1 km/s, while the crust layer had 4.60 km/s. The sedimentary layer thickness in this region also varies between 2 km to 10 km. A relatively thick sediment layer of about 8 km to 10 km was observed in two locations, in East Kalimantan associated with the Kutai Basin and Northern part of Sumatera in the North Sumatera Basin, a two major oil producer basinal area in Indonesia. The Moho discontinuity was also found at depths that vary between 16 km to 50 km. In addition, the most shallow Moho depth is 16 km below the North Kalimantan and North part of West Java, while the deeper Moho depth of 50 km is located below East Kalimantan, Central Kalimantan, North Sumatera and South Sumatera.

The crustal structure of the southern Nain and Makkovik provinces of Labrador derived from refraction seismic data

2008 ◽  
Vol 45 (4) ◽  
pp. 465-481 ◽  
Author(s):  
Thomas Funck ◽  
Annette K. Hansen ◽  
Ian D. Reid ◽  
Keith E. Louden
Keyword(s):  
Crustal Structure ◽  
Velocity Model ◽  
Seismic Profile ◽  
P Wave ◽  
Moho Depth ◽  
S Wave ◽  
Velocity Models ◽  
Refraction Seismic ◽  
Forward And Inverse Modeling ◽  
Lower Crustal

Data from a refraction seismic profile parallel to the coast of Labrador (Canada) were used to determine the crustal structure across the boundary of the Nain and Makkovik provinces, and to look for evidence for an offshore continuation of the Mesoproterozoic Nain Plutonic Suite (NPS). Seven seismometers recorded airgun shots along the 283 km long line. P- and S-wave velocity models were developed from forward and inverse modeling of travel times. The velocity model distinguishes three distinct zones. In the Saglek block of the Nain Province, the crust is divided into three layers with P-wave velocities between 5.8 and 6.9 km/s. Farther to the south, upper crustal velocities increase to 6.3–6.5 km/s and the Poisson’s ratio increases from 0.24 to 0.27. This zone correlates with a gravity low that is interpreted to outline the offshore continuation of the NPS. The upper crustal velocities are intermediate between anorthositic and granitoid rock samples collected from the NPS. A lower crustal reflector is limited to the area underneath the NPS and may be related to dioritic magmas. Mid-crustal and lower crustal velocities do not vary along the line and no underplating was detected. Within the Makkovik Province, upper crustal velocities of 5.9–6.2 km/s may indicate a dioritic composition similar to the Island Harbour Bay plutonic suite. Moho depth varies between 28 and 36 km with the maximum beneath the NPS. The variations could not be linked to effects of the Makkovikian orogeny but are thought to relate to Mesozoic rifting in Labrador Sea.

CRUSTAL STRUCTURE OF SE TIBET FROM RECEIVER FUNCTION METHOD

2018 ◽  
Author(s):  
Liangshu Wang ◽  
◽  
Xu Cao ◽  
Ning Mi ◽  
Dayong Yu ◽  
...  
Keyword(s):  
Crustal Structure ◽  
Function Method ◽  
Receiver Function ◽  
Se Tibet ◽  
Receiver Function Method

Crustal structure of La Palma and Tenerife (Canary Islands) from receiver function analysis.

2021 ◽  
Author(s):  
Víctor Ortega ◽  
Luca D'Auria ◽  
Iván Cabrera-Pérez ◽  
José Barrancos ◽  
Germán D. Padilla ◽  
...  
Keyword(s):  
Canary Islands ◽  
Crustal Structure ◽  
Arrival Time ◽  
Receiver Function ◽  
Function Analysis ◽  
Receiver Functions ◽  
Moho Depth ◽  
La Palma ◽  
Receiver Function Analysis ◽  
Volcanic Islands

<p>The receiver function analysis (RF) is a commonly used and well-established method to investigate crustal and mantle structures, removing the source, ray-path and instrument signatures. RF gives the unique signature of sharp seismic discontinuities and information about P and S wave velocities beneath a seismic station. In particular, using the direct P wave as a reference arrival time, and the relative arrival time of P-to-S (Ps) conversions and multiple reflections allow constraining the principal crustal structures and studying the effects of dipping interfaces and crustal layering.</p><p>We have applied RF analysis to the active volcanic islands of Tenerife and La Palma (Canary Islands). In recent years, both islands have increased their seismic activity and showed variation in geochemical parameters attributed to a magmatic-hydrothermal activity. Previous studies evidenced in La Palma and Tenerife a seismic Moho depth at 14 km and 12 and 15 km, respectively, but it is not clear because there are some others discontinuities under the stations (Lodge et al., 2012). Other RF studies indicated a depth of seismic Moho discontinuity between 16 and 30 km beneath the eastern islands to 11-15 km under the western isles, observing a thinning of the crust towards the west (Martinez-Arévalo et al., 2013). </p><p>We processed 313 teleseisms recorded by 17 stations for Tenerife and 252 teleseisms recorded by six stations for La Palma. Since the receiver functions display a significant complexity, as expected in oceanic volcanic islands, we applied a transdimensional inversion approach to image the 1D velocity structure beneath each station. We observe at least three discontinuities related with the oceanic crust and the overlying volcanic rocks layer. We compare the retrieved crustal structure with the seismicity recorded in recent years, showing how earthquakes have a radically different origin on these two islands. While in Tenerife they seem to be related to the dynamics of a shallow hydrothermal system, in La Palma they are related to magmatic intrusions in the upper mantle beneath the island.</p><p><strong>References</strong></p><p>Lodge, A., Nippress, S. E. J., Rietbrock, A., García-Yeguas, A., & Ibáñez, J. M. (2012). Evidence for magmatic underplating and partial melt beneath the Canary Islands derived using teleseismic receiver functions. Physics of the Earth and Planetary Interiors, 212, 44-54.</p><p>Martinez-Arevalo, C., de Lis Mancilla, F., Helffrich, G., & Garcia, A. (2013). Seismic evidence of a regional sublithospheric low velocity layer beneath the Canary Islands. Tectonophysics, 608, 586-599.</p>

scholarly journals Earthquake location in tectonic structures of the Alpine Chain: the case of the Constance Lake (Central Europe) seismic sequence

2021 ◽  
Author(s):  
Francesca D’Ajello Caracciolo ◽  
Rodolfo Console
Keyword(s):  
Central Europe ◽  
Velocity Model ◽  
Moho Depth ◽  
Seismic Sequence ◽  
Tectonic Structures ◽  
Study Region ◽  
Waveform Data ◽  
Seismic Stations ◽  
Velocity Models ◽  
Master Event

AbstractA set of four magnitude Ml ≥ 3.0 earthquakes including the magnitude Ml = 3.7 mainshock of the seismic sequence hitting the Lake Constance, Southern Germany, area in July–August 2019 was studied by means of bulletin and waveform data collected from 86 seismic stations of the Central Europe-Alpine region. The first single-event locations obtained using a uniform 1-D velocity model, and both fixed and free depths, showed residuals of the order of up ± 2.0 s, systematically affecting stations located in different areas of the study region. Namely, German stations to the northeast of the epicenters and French stations to the west exhibit negative residuals, while Italian stations located to the southeast are characterized by similarly large positive residuals. As a consequence, the epicentral coordinates were affected by a significant bias of the order of 4–5 km to the NNE. The locations were repeated applying a method that uses different velocity models for three groups of stations situated in different geological environments, obtaining more accurate locations. Moreover, the application of two methods of relative locations and joint hypocentral determination, without improving the absolute location of the master event, has shown that the sources of the four considered events are separated by distances of the order of one km both in horizontal coordinates and in depths. A particular attention has been paid to the geographical positions of the seismic stations used in the locations and their relationship with the known crustal features, such as the Moho depth and velocity anomalies in the studied region. Significant correlations between the observed travel time residuals and the crustal structure were obtained.

Structure beneath Queen Charlotte Sound from seismic-refraction and gravity interpretations

1992 ◽  
Vol 29 (7) ◽  
pp. 1509-1529 ◽  
Author(s):  
Tianson Yuan ◽  
G. D. Spence ◽  
R. D. Hyndman
Keyword(s):  
Crustal Structure ◽  
Velocity Structure ◽  
Sedimentary Basin ◽  
Single Channel ◽  
Velocity Variation ◽  
Moho Depth ◽  
High Porosity ◽  
Upper Crust ◽  
Low Velocity ◽  
Data Set

A combined multichannel seismic reflection and refraction survey was carried out in July 1988 to study the Tertiary sedimentary basin architecture and formation and to define the crustal structure and associated plate interactions in the Queen Charlotte Islands region. Simultaneously with the collection of the multichannel reflection data, refractions and wide-angle reflections from the airgun array shots were recorded on single-channel seismographs distributed on land around Hecate Strait and Queen Charlotte Sound. For this paper a subset of the resulting data set was chosen to study the crustal structure in Queen Charlotte Sound and the nearby subduction zone.Two-dimensional ray tracing and synthetic seismogram modelling produced a velocity structure model in Queen Charlotte Sound. On a margin-parallel line, Moho depth was modelled at 27 km off southern Moresby Island but only 23 km north of Vancouver Island. Excluding the approximately 5 km of the Tertiary sediments, the crust in the latter area is only about 18 km thick, suggesting substantial crustal thinning in Queen Charlotte Sound. Such thinning of the crust supports an extensional mechanism for the origin of the sedimentary basin. Deep crustal layers with velocities of more than 7 km/s were interpreted in the southern portion of Queen Charlotte Sound and beneath the continental margin. They could represent high-velocity material emplaced in the crust from earlier subduction episodes or mafic intrusion associated with the Tertiary volcanics.Seismic velocities of both sediment and upper crust layers are lower in the southern part of Queen Charlotte Sound than in the region near Moresby Island. Well velocity logs indicate a similar velocity variation. Gravity modelling along the survey line parallel to the margin provides additional constraints on the structure. The data require lower densities in the sediment and upper crust of southern Queen Charlotte Sound. The low-velocity, low-density sediments in the south correspond to high-porosity marine sediments found in wells in that region and contrast with lower porosity nonmarine sediments in wells farther north.

Sign in / Sign up

Export Citation Format

Share Document