-- Crust of the Oman Ophiolite and its Lithosphere --
In autumn 2013 we deployed a passive seismic network in northern Oman to precise the present-day geometry of the worlds reference ophiolite and the continental lithosphere beneath it. Fourty broadband seismometers, supplied by the Geophysical Instrument Pool Potsdam (GIPP) were operated until February 2016 in the area of the Oman Mountains from Ras al Hadd in the far easternmost corner of the Arabian Plate to the border of the United Arab Emirates in the northernmost corner of Oman (Fig. 1). The network consisted of thirty Güralp CMG-3ESP Compact, six Trillium 120 PA and four STS-2 seismometers, all equipped with an EarthData PR6-24 Logger as recording unit. The velocity response spectrum of the instruments is flat until 60s for the Güralp, and 120s for the Trillium and STS-2. These varying instrument characteristics, as well as the locations of the permanent seismic network operated by the EMC have been taken into consideration in the network design to achieve a homogeneous distribution of long-period data.
A formal collaboration between Christian-Albrechts-Universität zu Kiel and the Earthquake Monitoring Center in Oman has been established and facilitates data exchange. Prior to the deployment of the temporary network in 2013, the Oman Seismic Network was upgraded to be fully equipped with broadband instruments. Our final data set thus consists of continuous seismic recordings of 50 broadband seismometers covering an area of ca. 500 x 200km and with a station spacing between 20-60 km. The network is densified along a profile across the central part of the ophiolite, to include a high-resolution 2-D profile which will establish a link between locally high-resolution imaging to state-of-the-art 3D tomographic models.
After an embargo period of 4 years, data from the temporary COOL network will be freely available through GEOFON data center at GFZ Potsdam, Germany. See also the FDSN project page. The data are registered under network name '5H' and station names are 'COO01' through 'COO53'.
Fig. 1: Tectonic overview map and COOL network in northern Oman. Temporary COOL broadband seismometers are largely CMG-3ESP Compact (yellow triangles), Trillium 120PA (yellow triangles with green dot) and STS-2 (yellow triangles with blue dot). Additional seismometers in the area include permanent broadband sites of the Earthquake Monitoring Center (EMC) in Oman (green triangles) and from the Dubai and UAE seismic networks (orange triangles and dots). Red dots mark seismicity from 2012-2014 as recorded by the EMC and the black solid line roughly outlines the Semail ophiolite.
Fig. 2: Regional context of the COOL network (yellow triangles). Seismic data is freely available from permanent (dark blue triangles, encircled are GSN stations RAYN (west) and UOSS (east)) and temporary (light blue triangles) seismic stations, additional data from national seismic networks in Oman and UAE (green triangles) is not distributed through global data centers. Seismicity from the EHB catalogue is shown with color-coded source depth.
Fig. 3: Data example of regional event in the Red Sea, mb=5.9, recorded on the COOL network in northern Oman.