Earthquake swarm in the non-volcanic area north of Harrat Lunayyir, western Saudi Arabia: observations and imaging
Research output: Contribution to journal › Conference article › Research › peer-review
We report on an unusual earthquake swarm in a non-volcanic area of western Saudi Arabia. Since March 2017, hundreds of earthquakes were recorded, reaching magnitude Ml 3.7, which occurred within a very narrowly defined rock volume. The seismicity is shallow, mostly between 4 to 8 km depths, with some events reaching as deep as 16 km. One set of events aligns into a well-defined horizontal tube of 2 km height, 1 km width, and 4-5 km E-W extent. Other event clusters exist, but are less well-defined. The focal mechanism solutions of the largest earthquakes indicate normal faulting, which agree with the regional stress field. The earthquake swarm occurs 75 km NW of Harrat Lunayyir. However, the area of interest doesn't seem to be associated with the well-known volcanic area of Harrat Lunayyir, which experienced a magmatic dike intrusion in 2009 with intense seismic activity (including a surface rupturing Mw 5.7 earthquake). Furthermore, the study area is characterized by a complex shear system, which host gold mineralization. Therefore, the exact origin of the swarm sequence is enigmatic as it's the first of its kind in this region. By using continuous seismological data recorded by the Saudi Geological Survey (SGS) that operates three permanent seismic stations and a temporary network of 11 broadband sensors, we analyze the seismic patterns in space and time. For the verified detected events, we assemble the body wave arrival times that are inverted for the velocity structures along with events hypocenters to investigate possible causes of this swarm sequence, that is, whether the activity is of tectonic- or hydro-thermal origin.
Original language | English |
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Journal | American Geophysical Union, Fall Meeting 2017 |
Volume | 53 |
Publication status | Published - 1 Dec 2017 |
Externally published | Yes |
- 7209 Earthquake dynamics, SEISMOLOGY, 7215 Earthquake source observations, 7221 Paleoseismology, 7230 Seismicity and tectonics
Research areas
Links
- http://adsabs.harvard.edu/abs/2017AGUFM.S53B0690Y
Final published version
ID: 303366917