Abstract:

DanSeis: Seismology and Deep Science
Hans Thybo, Geology Section, IGN, University of Copenhagen

Danseis is a new national infrastructure for amphibious and onshore seismology, which is open for use in temporary projects to all researchers in Denmark after application. It was funded in 2011 by a grant of 25 Mkr from the Ministry of Science to University of Copenhagen (KU). The infrastructure is managed by KU together with a steering group (AU, GEUS, KU, DTU) appointed by Geocentre Denmark. The pool of instruments consists of:

• 20 SP-OBS (Short-Period, 4.5 Hz, Ocean Bottom Seismographs)
• 16 BB-OBS (Broad-Band with 120s Trillium Light sensor)
• 35 Trillium Seismometers (240 s) and
• 10 Trillium Light sensors (120 s) with Nanometrics dataloggers

This new pool of instruments provides unique opportunity to Danish researchers for carrying out combined off- and onshore seismological experiments. Some instruments are already in use in an international, collaborative experiment in northern Scandinavia (ScanArray), which involves AU and KU.
I will provide an overview of the infrastructure and opportunities for its use. Examples discussed will include some relevant scientific results from our group in geophysics at KU, including the discovery of the “Mid-Lithospheric Discontinuity”, heterogeneity of mantle densities and links to basin formation, crustal and mantle structure of the continents around the North Atlantic Ocean and implications for isostasy, and the new concept of “magma-compensated crustal thinning” at continental rift zones.
As an example of application of DanSeis to fundamental scientific problems, I will also present the idea of a first combined experiment (ICEPLUME) which is being planned in international collaboration to test the hypothesis of a mantle plume below Iceland. This experiment will involve deployment of BB-OBS in the area within 1000 km radius around Iceland as well as onshore on the surrounding continents in order to achieve resolution of teleseismic tomography down to at least 1200 km depth.