We present the up-to-date seismicity associated with the North Tabriz fault 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, KOERI-RETMC and USGS 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 North Tabriz fault.
- The yellow line segments, ‘NW-SE’, on the maps show the section. Earthquakes within a 20 km range are projected in the section.
- 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 green line along the left axis of each figure is the projection of the surface ruptures associated with the devastating earthquakes of 26 April 1721 (M~7.7) and 8 January 1780 (M~7.7) along the North Tabriz fault (Ambraseys and Melville, 2005).
- The thick red line segments, labeled A and B, on the maps and also along the right axis of each figure represent barriers. Most likely these silent fault segments will release the main seismic energy during their rupture.
- The thick red unlabeled line segment on the maps represents an uncertain barrier along the Turkmanchay-Ardabil section.
- The earthquake data to the west of 44.2° E is obtained from the KOERI database.
- The earthquake data for the rest of the map area is obtained from the IRSC catalog for the post-2006 period and from the USGS database for earlier times.
- Not necessarily every event along the section has the same mechanism as that of the North Tabriz fault. This is especially the case for the western and eastern segments.
Click to open the page for the 2019/11/07 Turkmanchay earthquake.Click to open map 1a, map 1b or figure 1c Click to open map 2a, map 2b or figure 2c Click to open map 3a, map 3b or figure 3c Click to open map 4a, map 4b or figure 4c Click to open map 5a, map 5b or figure 5c Click to open map 6a, map 6b or figure 6c Click to open map 7a, map 7b or figure 7c Click to open map 8a, map 8b or figure 8c
The earthquake data for this project is obtained from (i) the “Iranian Seismological Center” (IRSC) of the Institute of Geophysics, University of Tehran, (ii) the “Regional Earthquake-Tsunami Monitoring Center” (RETMC) of the Kandilli Observatory and Earthquake Research Institute and (iii) the US Geological Survey (USGS). 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).
- Ambraseys NN, Melville CP. A History of Persian Earthquakes. Cambridge university press; 2005.
- 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.