Black Forest Observatory (Schiltach)
Heubach 206
D-77709 Wolfach
Germany
Email:
Walter.Zuern@gpi.uni-karlsruhe.de
poster/oral: poster
| The 10 m long invar-wire strainmeters at BFO have recorded the twisting mode oT2 clearly after 5 large earthquakes now: Macquarie ridge 1989, Shikotan 1994, Balleny Islands 1998, Wharton basin 2000 and Peru 2001. The 120-degree array can be used to determine shear strain on any vertical plane as well as areal strain. The observations in shear of the fundamental toroidal mode are corroborated by its absence in areal strain. The strain array is described and the 5 observations will be shown. Noise correlated with local barometric pressure can be partially removed from the data, but shows up mainly in areal strain and much less in shear. |