Date post: | 17-Jan-2017 |
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Engineering |
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The IMAGE passive seismic project on Reykjanes peninsula, Iceland
GEORG Geothermal Workshop 2016, Reykjavík
Hanna Blanck, 24.11.2016
DAS (distributed acoustic sensing) technology
− Passive sensor cable
− Only the fiber optic cable is subject to the temperatures in the borehole
− Higher temperature tolerance than conventional sensors
− Possible recording in > 200°C
− Simulteneous data aquisition over long distances (several km)
− Sampling with high spatial and temporal resolution
− Test of DAS method for borehole and surface seismic measurements
− 9 days of recording
− Active shots and passive recording
Active recordings
- Hammer seismics
- Distance along fiber calculated from signal travel time
- hammer shots every 250 to 500 m along the surface cable
- to locate individual traces for spatial distribution
Summary/Outlook
- 2066 earthquakes recorded in 16 month
- Tomographic studies are ongoing
- DAS technology is well suited to monitor seismic signals in magmatic environments
- Focal mechanisms (ÍSOR)
- Ambient noise techniques (GFZ, TNO)
- Seismic interferometry (TNO)