Mud volcano activity: Evidence of seismicity on the Makran coast, southeastern Iran
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AzizOllah Tajvar , Ali Sheikhbahai  |
Department of Oceanography, Faculty of Marine Science, Chabahar Maritime University, Chabahar, Iran , tajvar@cmu.ac.ir |
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Abstract: (62 Views) |
A mud volcano is a geological phenomenon that forms as a dome-shaped feature and sometimes as a small basin. Most of the world's mud volcanoes have formed in active tectonic zones such as orogenic belts and subduction zones. One of the most important tectonic zones that contains a large number of mud volcanoes is the Makran accretionary wedge in southeastern Iran. The subduction of the Oman oceanic plate under the Eurasian continental plate of Iran and Pakistan has caused the formation of the accretionary prism, which has played a significant role in the formation and eruption of mud volcanoes and also controls the seismic behavior of this region. Therefore, the present study, by investigating the tectonic characteristics of the Makran zone, analyzed the relationship between the seismicity of this region and mud volcano eruption and compared it with similar cases in the world.
In this study, first, by collecting existing data and using satellite images, the tectonic characteristics of the Makran zone were discussed, and by using ArcGis 10.4. fault distribution map was prepared. Then, by deducing the history of earthquakes in the Makran zone, the seismicity formula of this region was calculated and the return period for earthquakes of different magnitudes was estimated. Finally, the relationship between the occurrence of earthquakes and mud volcani activity in the Makran zone was investigated and compared with similar cases around the world.
Based on the results, faults with a general E-W trend throughout the Makran zone play an important role in the occurrence of earthquakes. The most important of these faults, from south to north, are the main Makran thrust, the Chahkhan thrust, the Qasr-e-Qand thrust, and the Bashagard thrust. Movement along each of these faults and their numerous branches causes earthquakes in this region. Based on the earthquakes that occurred in the Makran zone, the seismicity formula (logN=2.9-0.8Ms) of this region has been determined, and the return period for earthquakes with magnitudes of 5, 6, and 7 on the Richter scale has been calculated as once every 22 years, once every 158.5 years, and once every 1222 years, respectively. |
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Keywords: Mud volcano, Earthquakes, Subduction zone, Makran coast, Southeastern Iran |
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Type of Study: Research/ Original/ Regular Article |
Subject:
Coastal Oceanography Received: 2025/02/14 | Revised: 2025/03/10 | Accepted: 2025/03/10
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