We present the up-to-date seismicity associated with the Kopeh Dagh system as a series of space-time sections. The aim is to reveal the hidden orders and to facilitate prompt interpretation. The earthquake data is obtained from the IRSC and the ISC databases every minute. With new earthquakes the figures and maps are updated immediately; otherwise, they are regenerated every hour. The following points should be considered regarding the images.
- There are 8 figures showing time-space sections of seismicity for different periods. Earthquakes are projected on the line segments that represent the Kopeh Dagh system.
- The yellow line segments, ‘SE-NW’, on the maps show the section. Earthquakes within a 40 km range are projected in the section. The large width of the zone covers a probable thrusting.
- For each figure X, there are 3 associated illustrations with a corresponding period. Xa shows the seismicity for the whole region, while Xb displays the events in the window around the section. Figure Xc shows the depth distribution of events along the section. Their links are given below each figure.
- The thick red line segments that are labeled A, B, C, and D on the maps and also along the right axis of each figure represent seismic gaps. Gaps B and C seem favorable for the next substantial ruptures in the system.
- The blue contours show the intensity, V to X, for the 1948/10/05 (Mw 7.3) Ashgabad earthquake (Sidorin, 2019). The conspicuous asymmetry of the contours in the NW-SE direction indicates a southeasterly rupture propagation. This emphasizes the potential risk for the inhabitants of the Dargaz valley.
- The thick magenta line segments along the left axis or within the figures show the projection of the intensity contour VIII for the 5 October 1948 (Mw 7.3) earthquake.
- The earthquake data for the post-2006 period is obtained from the IRSC catalog, while the ISC database is the data source for earlier times.
- Fault lines, thin green lines, for the Kopeh Dagh system are digitized from the figures in Walker (2017) and Sidorin (2019).
The earthquake data for this project is obtained from (i) the “Iranian Seismological Center” (IRSC) of the Institute of Geophysics, University of Tehran and (ii) the International Seismological Center (ISC). We appreciate these institutions for the release of their products to the public. The figures are produced by using the “Generic Mapping Tool” (GMT) and we thank the developers of the software (Wessel et al., 2013).
- Sidorin AY. Effects and Lessons of the 1948 Ashgabat Earthquake. Seismic Instruments. 2019;55:271–282.
- Walker R. nerc. Earthquakes withoth Frontiers. http://ewf.nerc.ac.uk/blog/. Published March 22, 2017. Accessed November 27, 2019.
- Wessel P, Smith WH, Scharroo R, Luis J, Wobbe F. Generic mapping tools: improved version released. Eos, Transactions American Geophysical Union. 2013;94:409–410.