Preliminary Magnitude of Completeness Quantification of Improved BMKG Catalog (2008-2016) in Indonesian Region

41st HAGI Annual Convention and Exhibition 2016

Diantari, H.C.^1 ; Suryanto, W.^1 ; Anggraini, A.^1 ; Irnaka, T.M.^1 ; Susilanto, P.^2 ; Ngadmanto, D.^2

Geophysics Laboratory, Department of Physics, Faculty of Mathematics and Natural Sciences, Yogyakarta, Indonesia^1

Meteorological Climatological and Geophysics Agency (BMKG), Indonesia^2

关键词: Earthquake catalogs;    Eastern regions;    Frequency-magnitude distribution;    Maximum likelihood methods;    Moment magnitudes;    Seismograph networks;    Space and time;    Temporal variation;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/132/1/012026/pdf
DOI  :  10.1088/1755-1315/132/1/012026

来源: IOP

【 摘 要 】

We present a magnitude of completeness (Mc) quantification based on BMKG improved earthquake catalog which generated from Ina-TEWS seismograph network. The Mc quantification can help us determine the lowest magnitude which can be recorded perfectly as a function of space and time. We use the BMKG improved earthquake catalog from 2008 to 2016 which has been converted to moment magnitude (Mw) and declustered. The value of Mc is computed by determining the initial point of deviation patterns in Frequency Magnitude Distribution (FMD) chart following the Gutenberg-Richter equations. In the next step, we calculate the temporal variation of Mc and b-value using maximum likelihood method annually. We found that the Mc value is decreasing and produced a varying b-value. It indicates that the development of seismograph network from 2008 to 2016 can affect the value of Mc although it is not significant. We analyze temporal variation of Mc value, and correlate it with the spatial distribution of seismograph in Indonesia. The spatial distribution of seismograph installation shows that the western part of Indonesia has more dense seismograph compared to the eastern region. However, the eastern part of Indonesia has a high level of seismicity compared to the western region. Based upon the results, additional seismograph installation in the eastern part of Indonesia should be taken into consideration.