| dc.creator |
FAHRUDDIN, FAHRUDDIN |
|
| dc.date.accessioned |
2020-06-15T03:57:36Z |
|
| dc.date.available |
2020-06-15T03:57:36Z |
|
| dc.identifier |
http://eprints.ulm.ac.id/1532/7/Abstract%20Fahruddin.JPG |
|
| dc.identifier |
FAHRUDDIN, FAHRUDDIN Search for mantle seismic discontinuities beneath northern Kalimantan, central Indonesia: A preliminary result of employing SS precursors. Search for mantle seismic discontinuities beneath northern Kalimantan, central Indonesia: A preliminary result of employing SS precursors. |
|
| dc.identifier.uri |
https://repo-dosen.ulm.ac.id//handle/123456789/10121 |
|
| dc.description |
Kalimantan, located in the island of Borneo, represents a rare region in Indonesia, which has a
relatively low seismic activity as it is located far from subduction zones. The number of existing
seismic stations in this region is also quite low. Therefore, in order to investigate the mantle
discontinuities beneath Kalimantan, we employed SS precursor data with SS bounce points within
the study region (northern Borneo and its surroundings), located more or less halfway between
earthquakes and receivers. In this study, we used data from several events in Fiji and Tonga
recorded by the seismographic stations UOSS (the United Arab Emirates) and RAYN (Saudi
Arabia). We used SS precursors resulting from a strict data selection with criteria: (i) earthquake
depths 75 km; (ii) earthquake magnitudes > 5.8; and (iii) epicentral distances between 120o and
145o. There are two main steps in the data processing: (i) seismogram stacking by employing a
Radon transform and (ii) ray tracing by using a shooting method. From the stacking results we
obtained a strong energy focus in the Radon domain associated with a discontinuity at ~690 km
depth. Another energy focus – which is weak – was also observed that is related to a discontinuity
at ~290 km depth. We did not observe the global 410-km discontinuity beneath the study region.
We focused our discussion on the strong discontinuity at the depth of 690 km, which is quite
significantly deeper than the global average of seismic discontinuity; i.e., at 660 km depth. This
observation is related to the subducted oceanic lithospheric slab that penetrates into the lower
mantle and is then deflected horizontally below the 660 km depth beneath the study region before
going down to a depth of at least 1500 km as depicted by previous tomographic models. |
|
| dc.format |
image |
|
| dc.relation |
http://ceser.in/ceserp/index.php/ijts/article/view/4749 |
|
| dc.relation |
http://eprints.ulm.ac.id/1532/ |
|
| dc.subject |
AI Indexes (General) |
|
| dc.title |
Search for mantle seismic discontinuities beneath northern Kalimantan, central Indonesia: A preliminary result of employing SS precursors |
|
| dc.type |
Article |
|
| dc.type |
PeerReviewed |
|