 |
| Titel |
Towards Crustal Structure of Java Island (Sunda Arc) from Ambient Seismic Noise Tomography |
| VerfasserIn |
Sri Widiyantoro, Zulfakriza Zulhan, Agustya Martha, Erdinc Saygin, Phil Cummins |
| Konferenz |
EGU General Assembly 2015
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250103188
|
| Publikation (Nr.) |
 EGU/EGU2015-2589.pdf |
|
|
|
|
|
| Zusammenfassung |
| In our previous studies, P- and S-wave velocity structures beneath the Sunda Arc
were
successfully imaged using a global data set and a nested regional-global tomographic
method was employed. To obtain more detailed P- and S-wave velocity structures
beneath Java, in the central part of the Sunda Arc, we then used local data sets,
i.e.
newline from the MErapi AMphibious EXperiment (MERAMEX) and the Meteorological,
Climatological and Geophysical Agency (MCGA), as well as employed a double-difference
technique for tomographic imaging. The results of the imaging show e.g. that P-
and
S-wave velocities are significantly reduced in the uppermost mantle beneath central
Java.
In order to obtain detailed crustal structure information beneath Java, the Ambient
Noise
Tomography (ANT) method was used. The application of this method to the MERAMEX
data has produced a good crustal model beneath central Java. We continue our experiment
to
image crustal structure of eastern Java. We have used seismic waveform data recorded by
22
MCGA stationary seismographic stations and 25 portable seismographs installed for 2 to
8
weeks. The data were processed to obtain waveforms of cross-correlated noise
between
pairs of seismographic stations. Our preliminary results presented here indicate
that the Kendeng zone, an area of low gravity anomaly, is associated with a low
velocity zone. On the other hand, the southern mountain range, which has a high
gravity anomaly, is related to a high velocity anomaly (as shown by our tomographic
images).
In future work we will install more seismographic stations in eastern Java as well as
in
western Java to conduct ANT imaging for the whole of Java Island. The expected
result
combined with the mantle velocity models resulting from our body wave tomography
will
allow for accurate location of earthquake hypocenters and determination of regional
tectonic
structures. Both of these are valuable for understanding seismic hazard in Java, the
most
densely populated island in the world. |
|
|
|
|
|
|