Geodetic strain of Greece in the interval 1892-1992

Davies, R; England, P; Parsons, B; Billiris, H; Paradissis, D; Veis, G

dc.contributor.author	Davies, R	en
dc.contributor.author	England, P	en
dc.contributor.author	Parsons, B	en
dc.contributor.author	Billiris, H	en
dc.contributor.author	Paradissis, D	en
dc.contributor.author	Veis, G	en
dc.date.accessioned	2014-03-01T01:12:57Z
dc.date.available	2014-03-01T01:12:57Z
dc.date.issued	1997	en
dc.identifier.issn	01480227	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12289
dc.subject	Global Position System	en
dc.subject	First Order	en
dc.subject	Low Pressure	en
dc.subject.classification	Geochemistry & Geophysics	en
dc.subject.other	deformation	en
dc.subject.other	geodesy	en
dc.subject.other	GPS	en
dc.subject.other	strain	en
dc.subject.other	Greece	en
dc.title	Geodetic strain of Greece in the interval 1892-1992	en
heal.type	journalArticle	en
heal.identifier.primary	10.1029/97JB01644	en
heal.identifier.secondary	http://dx.doi.org/10.1029/97JB01644	en
heal.language	English	en
heal.publicationDate	1997	en
heal.abstract	A first-order triangulation of Greece was carried out in the 1890s, Reoccupation, using Global Positioning System receivers, of 46 of the 93 original markers yielded estimates of the deformation of the region over the intervening interval. Broad regions have similar geodetic strain over the 100-year time span. Strain north of the Gulf of Korinthos is predominantly north-south extension, though with a significant east-west component. The central Peloponnisos is relatively stable, whereas the gulfs of the southern Peloponnisos are all characterized by uniaxial east-west extension. The seismic expression of strain for the entire region, calculated from the seismic moment tensors of earthquakes of M-s greater than or equal to 5.8 during the past 100 years, accounts for only 20-50% of the geodetically determined strain. At a scale of 50-100 km, the fraction of the strain that is expressed seismically varies much more than this range. In particular, whereas seismic strain in the eastern Gulf of Korinthos over the past 100 years is commensurate with the geodetic strain, there is rapid extension across the western Gulf of Korinthos (similar to 0.3 mu strain yr(-1)), with negligible seismic strain for the 100 year period prior to 1992. The Egion earthquake of June 1995 in the western Gulf of Korinthos released only a small proportion (less than or equal to 20%) of the elastic strain that had accumulated in that region. The observed distribution of displacements can be explained by the relative rotation of two plates with a broad accommodation zone between them, but it is equally consistent with the deformation that would be expected of a sheet of fluid moving toward a low-pressure boundary at the Hellenic Trench. A simple calculation implies that if the region does behave as a fluid, then its effective viscosity is similar to 10(22)-10(23) Pa s. Such viscosities are consistent with the deformation of a lithosphere obeying a rheological law similar to that obtained for olivine in the laboratory.	en
heal.publisher	AMER GEOPHYSICAL UNION	en
heal.journalName	Journal of Geophysical Research B: Solid Earth	en
dc.identifier.doi	10.1029/97JB01644	en
dc.identifier.isi	ISI:A1997YF51100012	en
dc.identifier.volume	102	en
dc.identifier.issue	11	en
dc.identifier.spage	24571	en
dc.identifier.epage	24588	en