Computer Science
Scientific paper
Feb 1987
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987e%26psl..81..379h&link_type=abstract
Earth and Planetary Science Letters, Volume 81, Issue 4, p. 379-396.
Computer Science
18
Scientific paper
During March and April 1984, a temporary network of 29 portable stations was operated in the region of the Mygdonian graben near Thessaloniki (northern Greece), where a destructive earthquake (Ms = 6.5) had occurred in the Summer of 1978. During a period of six weeks we recorded 540 earthquakes with magnitudes ranging from -0.2 to 3.0. From this set of data, 254 events are selected which according to us have a precision in epicenter and depth better than 1.5 km. A total of 54 single-event focal mechanisms have been determined.
The seismicity and focal mechanisms show a rather complex pattern. There are no clear individual faults, but the E-W and NW-SE striking zones show N-S extension. Zones striking NNE-SSW show dextral strike-slip motion but NW-SE zones with sinistral strike-slip are also observed.
In the center of the graben where the 1978 earthquake was located, we observe several thrust mechanisms distributed in two groups showing either NW-SE or E-W compression; these earthquakes seem to be located 2 km above the earthquakes showing normal mechanisms.
The mean direction of the T-axes, found from the focal mechanisms, trends N15° and dips sub-horizontal.
We propose a model for the formation and evolution of a complex graben system comprising several stages. In the initial stage the deformation occurs along pre-existing NW-SE or NNE-SSW faults, with normal or strike-slip movements. In the second stage, a new, E-W trending group of normal faults is formed over the ancient fault network. These new faults have a direction perpendicular to the mean T-axis and accommodate better the actual state of stress. At this stage the initial faults adjust to the deformation produced by the E-W trending new faults, and may constitute geometric barriers to the evolution of the new normal faults.
Christodoulou A. A.
Hatzfeld Denis
Hatzidimitriou Panagiotis M.
Panagiotopoulos Dimitris
Scordilis E. M.
No associations
LandOfFree
A microearthquake study of the Mygdonian graben (northern Greece) does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A microearthquake study of the Mygdonian graben (northern Greece), we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A microearthquake study of the Mygdonian graben (northern Greece) will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1012108