G13A-0998
Re-investigation of slip rate along the southern part of the Sumatran Fault Zone using SuMo GPS network

Monday, 14 December 2015
Poster Hall (Moscone South)
Iwan Hermawan1, Ashar muda Lubis2, Rio Sahputra2, Emma M. Hill3, Kerry Sieh3, Lujia Feng1, Rino Salman1 and Nugroho Hananto4, (1)Earth Observatory of Singapore, Singapore, Singapore, (2)Bengkulu University, Department of Physics, Faculty of Mathematics and Sciences, Bengkulu, Indonesia, (3)Nanyang Technological University, Singapore, Singapore, (4)Indonesian Institute of Sciences, Bandung, Indonesia
Abstract:
The Sumatran Fault Zone (SFZ) accommodates a significant component of the strike-slip motion of oblique convergence along the Sumatra subduction zone. Previous studies have suggested that the slip rates of the SFZ increase from south to north. However, recent work shows that the slip rates may not vary along the SFZ [Bradley et al., 2015]. New data are needed to help confirm these results, and to assess slip-rate variability and fault segmentation in more detail. This information is vital for seismic hazard assessment for the region. We have therefore installed and operated the SuMo (Sumatran Fault Monitoring) network, a dense GPS campaign network focused around the SFZ.

From 2013-2015 we selected and installed 32 GPS monuments over the southern part of the SFZ. The network comprises of three transects. The first transect is around the location of the great 1900 earthquake, at the Musi segment. Two transects cover the Manna segment, which saw its last great earthquake in 1893, and the Kumering segment, which saw two great earthquakes in 1933 (M 7.5) and 1994 (M 7.0).

We have now conducted three GPS campaign surveys for these stations (3-4 days of measurement for each occupation site), and established 5 semi-permanent cGPS stations in the area. The processed data show that the campaigns sites are still too premature to be used for estimating slip rates, but from the preliminary results for the semi-permanent stations we may see our first signal of deformation. More data from future survey campaigns will help us to estimated revised slip rates.

In addition to the science goals for our project, we are this year starting a project called "SuMo Goes to School," which will aim to disseminate information on our science to the schools that house the SuMo GPS stations. The SuMo project also achieves capacity building by training students from Bengkulu University in geodesy and campaign GPS survey techniques.

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