Microearthquake distribution in the Lake Aswan area, Egypt

• Autorzy: Hassoup A.
• Języki publikacji: EN

Abstrakty

EN

The temporal evolution of the Lake Aswan seismicity in Egypt over a 13-year period, from 1982 to 1995, is characterized by two separate sequences which occurred in August 1982 and June 1987 and a nearly continuous low-level activity over the remainder of the period. This study presents details of the space-time analyses of the two sequences. A nonlinear inversion method was used to relocate 200 events. The distribution of August 1982 foci exhibits asperity deformation; its center is located at 23.58°N, 32.57°E and 17 km depth. The foci distribution forms a zone dipping generally to the southwest. The June 1987 foci are distributed in a nearly vertical zone between 5 and 11 km depth, with epicentral coordinate centered at 23.57°N and 32.68°E. The August 1982 sequence is of foreshock-mainshock-aftershock type with a b-value of 0.8 and an aftershock decay rate of 0.78. The June 1987 activity is characterized by a b-value of 0.6 and is made up of two successive swarm bursts, which took place on June 17 and 19. The aftershock decay rates of these bursts are calculated as 1 and 0.99, respectively. The August 1982 cluster is of small amplitude and associated with a high background level. The June 1987 anomaly is of larger amplitude originating in a nearly zero background level. Our results suggest the Lake Aswan seismicity consists of the seismic zones with different characteristics.

Słowa kluczowe

EN

earthquake distribution; earthquake clustering; Lake Aswan

• Wydawca: Instytut Geofizyki PAN
• Czasopismo: Acta Geophysica Polonica
• Rocznik: 2001
• Tom: Vol. 49, nr 3
• Strony: 317--330
• Opis fizyczny: Bibliogr. 25 poz.

Twórcy

autor

Hassoup A.

• National Research Institute of Astronomy and Geophysics,Cairo, Egypt,