We present the up-to-date seismicity associated with the North and East Lut faults 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 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.

  1. There are 8 figures showing time-space sections of seismicity for different periods. Earthquakes are projected on the line segments that represent the North and East Lut faults.
  2. The yellow line segments, ‘S-N’, on the maps show the section. Earthquakes within a 20 km range are projected in the section.
  3. 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.
  4. The thick red line segments that are labeled A, B, and C on the maps and also along the right axis of each figure represent seismic gaps. Gap A is an ideal candidate for the next rupture of the system. The consecutive rupture of the earthquakes mentioned above and their time intervals support this viewpoint.
  5. The unlabeled red line segments show the seismic gaps in the West Lut fault system.
  6. The thick magenta line segments along the left axis of each figure are the projection of the surface ruptures associated with the devastating earthquakes of 31 August 1968 (Mw 7.1), 14 November 1979 (Mw 6.6), 27 November 1979 (Mw 7.1) and 10 May 1997 (Mw 7.3) along the North and East Lut faults (Berberian and Yeats, 1999).
  7. The thick magenta line, 160 to 220 km, along the left axis of the figures represents surface rupture associated with an earthquake in 1838 (M ~7) (Ambraseys and Melville, 2005). On the maps, it locates immediately south of Gap B. The magenta surface rupture to the southeast of Gap A is also assigned to earthquakes in 1838 (Ambraseys and Melville, 2005).
  8. The earthquake data for the post-2006 period is obtained from the IRSC catalog, while the USGS database is the data source for earlier times.
Elements and details that may become unrecognizable due to dense seismicity or background color of the maps.
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

Acknowledgment

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 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).

References

  • Ambraseys NN, Melville CP. A History of Persian Earthquakes. Cambridge university press; 2005.
  • Berberian M, Yeats RS. Patterns of historical earthquake rupture in the Iranian Plateau. Bulletin of the Seismological society of America. 1999;89:120–139.
  • 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.