OMAN SEISMOLOGICAL NETWORK AND EARTHQUAKE MONITORING

Information on historical earthquakes and the surrounding seismically active tectonics along the Makran subduction zone, the Gulf of Aden, and the Zagross collision zone, along with the fast development of Oman in the last three decades necessitated the establishment of a local seismic network to monitor seismic activity in and around Oman for the assessment of earthquake hazard in the country. A multiphase seismic network was determined in order to assess and mitigate earthquake hazard in Oman. The first phase of Oman Seismological Network (OSN) consisted of ten three-component short period sensors (SS-1) remote seismic stations completed in July 2001. Seven of the remote stations are located in the north and three are located in the southern Oman regions. Factors considered in station site selection are the regional crustal faults, concentration of population and infrastructures, station accessibility, rock foundation and low seismic noise level. The second phase consisted of three broadband (STS-2) seismic stations completed in 2004. The broadband stations are located in Musandam, Al-Buraimi, and Shalim regions. Seismological data are continuously transmitted via the VSAT satellite and received at the Earthquake Monitoring Center (EMC) at Sultan Qaboos University (SQU) in real-time. The system has been functioning properly with very little interruption since the beginning of operation. The EMC at SQU commenced seismic recording in 2001. The EMC monitor and analyze earthquake recordings inside and outside Oman. Earthquakes information transmitted from the 13 stations at various locations in Oman to the EMC where the Antelope Software performs an automated initial stage determination of location and magnitude for the detected earthquakes. The EMC staff then review the data analyzed by the Antelope system to better locate the recorded seismic events and store them in OSN database. Over 1400 local and regional earthquakes and more than 3200 teleseismic earthquakes have been recorded and analyzed by the EMC since the inception of the OSN in the year 2001. Most of these events were located along the known plate boundary of the Arabian plate and in seismically active zones in the world. Few events have been detected and located in Oman and only five of these earthquakes are felt by Oman residents. An increase of small earthquake detection has been noticed in the northern portion of Oman and United Arab Emirates since the establishment of Dubai seismic network and the start of realtime