TY - JOUR ID - 89267 TI - Calibration of IASPEI Standard Broad-band Magnitude mB for Iranian Plateau Earthquakes JO - Journal of the Earth and Space Physics JA - JESPHYS LA - en SN - 2538-371X AU - Kiani, Mehran AU - Moradi, Ali AD - Department of Seismology, Institute of Geophysics, University of Tehran, Tehran, Iran. E-mail: mehran.kiani@alumni.ut.ac.ir AD - Corresponding Author, Department of Seismology, Institute of Geophysics, University of Tehran, Tehran, Iran. E-mail: asmoradi@ut.ac.ir Y1 - 2023 PY - 2023 VL - 48 IS - 4 SP - 125 EP - 135 KW - MB KW - Mw KW - Earthquake Magnitude KW - calibration KW - Iran Plateau DO - 10.22059/jesphys.2022.345010.1007444 N2 - Located in Alp-Himalayan belt and an active tectonic plate, Iran is annually struck by major earthquakes. Since shallow earthquakes cause considerable loss of lives and property in this region, using any method to decrease the time of magnitude estimation of great earthquakes is very important for making a prompt decision about what to do. To achieve this aim, mB was computed as a rapid estimator for 38 earthquakes with magnitudes greater than 6 occurred in Iran and adjacent areas (24°-44°N, 42°-66°E) from 1990 to 2018. The magnitudes that estimated by using the calibration function by Saul & Bormann (2007) have a standard error of 0.49 from Mw (in this study). Therefore, mB’s calibration function was modified. As a result, the magnitudes obtained are approximately equal to those of reported Mw (a standard error of 0.18). The calibration function acquired in this study for Iran’s earthquakes is lower than the mB’s global calibration function obtained by Saul & Bormann (2007). Their difference is nearly one unit at short distances, which can be related to the earthquakes located in subduction zones and plates boundaries used by Saul & Bormann (2007) that systemically have lower stress drops than intraplate earthquakes considered here. Thus it is needed to develop improved region-specific calibration functions for mB. However, the difference became smaller at distances greater than 20°. Consequently, this method and new calibration function can be employed to estimate magnitudes as early as possible across Iran plateau. UR - https://jesphys.ut.ac.ir/article_89267.html L1 - https://jesphys.ut.ac.ir/article_89267_e4f774fb589def729007dce668517973.pdf ER -