PRESENTATION OF APPLICATION OF GEODETIC TECHNIQUES

TO CRUSTAL DEFORMATIONGeomatics Departement

National Cheng-Kung UniversityTainan

HELLO!I Dewa Made Adindha Surya AM Firdaus IrsyadiIva Nurwauziyah

RELATIONSHIP BETWEEN FAULT AND EARTHQUAKE IN SUMATERA,

INDONESIA

IntroductionMethods and Data

ConclusionResult and Discussion

Outline

1.INTRODUCTION

“Indonesia is located at the triple junction of the Australian Plate, Eurasian Plate, and

Pacific Plate“

“The Australian Plate is converging with the southeastern segment of the Eurasian Plate, called the Sunda Plate. This plate motion is oblique to the

Sumatran Subduction Zone”

“Because of these complex tectonics, Indonesia is an earthquake-prone country.“

“The great Sumatra – Andaman earthquake and Tsunami of 2004 was dramatic

reminder of the importance of understanding the seismic and tsunami hazards of

subduction zones”

“Here, we shows the relationship between

those topics using two paper and what’s the

historical earthquake occured to understand

the patterns”

“There’s several earthquakes happen in Sumatran which are in March 2005 Sunda

Megathrust ruptured producing moment magnitude amount 8.6”

2.METHODS AND DATA

METHODS▹ Joint Inversion of Teleseismic▹ Strong Ground Motion Data

METHODS AND DATA

To estimate 2010 of the Mentawai tsunami earthquake rupture

process

DATA▹ IRIS – DMC and BMKG Station Near the mainshock

occured▹ InSAR and GPS measurement

To understand partial rupture of a locked path the Sumatera megathrust during 2017 earthquake sequence

3.RESULT AND DISCUSSION

Based on Paper 1 (Estimation of the 2010 Mentawai tsunami earthquake rupture process from joint inversion of

teleseismic and strong ground motion data)

Tectonic Map of the 2010 Mentawai Earthquake Region. An Expanded View of The Study Region is Shown in upright Corner.

Joint Inversion Result of the Mentawai Earthquake

Slip Distribution Map View for The Week After the Mainshock

“Paper 1 shows The 2010 Mentawai earthquake generated a locally

devastating tsunami much larger than expected based on the seismic magnitude.

”

“This paper identify this earthquake as a tsunami earthquake because of its excessively long

rupture duration and its generation of a greater than expected tsunami.”

“However, there are large differences in slip distributions from the different modeling methods

and datasets.”

“Although this paper cannot reconcile these complexities and large uncertainties on the amount

of slip still exist, this paper found the conclusion that the majority of slip occurred far from the

islands at very shallow depths to be robust”

Based on Paper 2 (Partial Rupture of Locked Patch of the Sumatra Megathrust during the 2007 Earthquake Secquence)

Patches with Strong Inteseismic Coupling on the Sunda Megathrust Coincide With Large Seismic Ruptures

Models of Megathrust Slip During the Mw = 8.4 and Mw = 7.9 Earthquakes Show

Principal Slip on Widely Separated Patches

Comparison of The Moment Release Deficit Accumulated Since the 1797 and 1833

Earthquakes

“Paper 2 shows shows that the rupture area of the 2007 Mentawai

earthquakes was confined to a subset of a locked portion that is surrounded by

creep during the interseismic period. ”

“Such permanent barriers, which are found to influence the down-dip extent as well as the

lateral extent of megathrust ruptures, can be imaged from the modelling of interseismic strain

except when they lie in stress shadows, inparticular along the up-dip portion of the plate interface”

“The complex spatio-temporal pattern of the 2007 rupture is probably related to the fact that it

produced much less slip than did historical earthquakes in the area. The 2007 ruptures released

only 25% of the deficit of moment that had accumulated since the last rupture.”

“This is probably the main reason that neither the slip-predictable nor the time-predictable

models apply, and why the 2007 earthquakes did not grow as big as the 1833 earthquake. This

supports the view that seismic asperities are probably not permanent features 28 but rather move

from one rupture to another within the area that is locked in the interseismic period”

“Such permanent barriers, which are found to influence the down-dip extent as well as the

lateral extent of megathrust ruptures, can be imaged from the modelling of interseismic strain

except when they lie in stress shadows, inparticular along the up-dip portion of the plate interface”

“Some of these barriers are most likely not permanent and are related to the slip in past

earthquakes. Whereas permanently creeping barriers should tend to favour some regularity and

similarity of earthquakes, the presence of non-permanent barriers due to the stress distribution left

over from previous ruptures is probably the major factor introducing irregularity, as observed in

dynamic fault models.”

4.CONCLUSION

First- These Earthquakes are correspond each other

- Besides, earthquake occurred because the fracture between two blocks of rock allows the blocks to move relative to each other and the movement may occur rapidly so earthquake happened

- The geographic of Sumatran shows the variety of topography such as volcanoes, seamount and etc triggered the tectonic plate activity around Sumatra.

Second- From two paper explains the historical of

earthquake happened in Sumatran

- From historical of earthquake in Sumatra, we can understand about the estimation of rupture processed

- It indicates that every earthquakes in Sumatra are related each other along subduction zone or coupling zone. It can influence one to another faults to move rapidly or slowly (creep) around Sumatra area.

CONCLUSION

THANK YOU!