A. Adi Martha¹ , E. Saygin² , P. Cummins³ , S. Widiyantoro⁴ , M. Masturyono¹

¹Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG), National Seismological Center, Jakarta, Indonesia
²University of Western Australia, Perth, WA, Australia
³Australian National University, Canberra, ACT, Australia
⁴Bandung Institute of Technology, Bandung, Indonesia

Abstract:

The eruption of a hot mud volcano (LUSI) in East Java is a disaster that resulted in enormous material loss. This eruption was located in areas rich in oil and gas. The eruption threatens a lot of people because there are many pipelines are located in this area. This eruption is not the first in the research area; there were already 13 occurrences at different locations and times. To generate the imaging of the subsurface beneath the research area, we use the ambient noise tomography method. We use seismic data that were recorded at 80 seismographs spread around East Java. We constructed the inter-station Rayleigh wave Green's functions through cross-correlations of the Z component of seismic noise recordings at 1400 pairs of stations. We used the Neighbourhood Algorithm to construct depth profiles of shear wave velocity (Vs). The results of the imaging showed the existences of low Vs anomaly beneath LUSI at a depth of 1.7km. Based on paleontological analyses, this anomaly is identical to the hot mud volcano. These anomalies are scattered beneath areas of the surface that have never experienced a mud volcano eruption, but the lowest anomalies are beneath the LUSI area and Madura Strait.