Probabilistic seismic hazard maps for the sultanate of Oman

Abstract

This study presents the results of the first probabilistic seismic hazard assessment (PSHA) in the framework of logic tree for Oman. The earthquake catalogue was homogenized, declustered, and used to define seismotectonic source model that characterizes the seismicity of Oman. Two seismic source models were used in the current study; the first consists of 26 seismic source zones, while the second is expressing the alternative view that seismicity is uniform along the entire Makran and Zagros zones. The recurrence parameters for all the seismogenic zones were determined using the doubly bounded exponential distribution except the zones of Makran, which were modelled using the characteristic distribution. Maximum earthquakes were determined and the horizontal ground accelerations in terms of geometric mean were calculated using ground-motion prediction relationships developed based upon seismic data obtained from active tectonic environments similar to those surrounding Oman. The alternative seismotectonic source models, maximum magnitude, and ground-motion prediction relationships were weighted and used to account for the epistemic uncertainty. Hazard maps at rock sites were produced for 5 % damped spectral acceleration (SA) values at 0.1, 0.2, 0.3, 1.0 and 2.0 s spectral periods as well as peak ground acceleration (PGA) for return periods of 475 and 2,475 years. The highest hazard is found in Khasab City with maximum SA at 0.2 s spectral period reaching 243 and 397 cm/s 2 for return periods 475 and 2,475 years, 123Nat ) 64:173-210 DOI 10.1007 respectively. The sensitivity analysis reveals that the choice of seismic source model and the ground-motion prediction equation influences the results most.

Tsunami hazard assessment along Diba-Oman and Diba-Al-Emirates coasts

“…The tsunamigenic source region that has the potential to affect the coasts of Diba Oman-UAE is delineated on the basis of historical earthquake records, tsunami data, and sea bathymetric data. The source mechanism and characteristics of the Probable Maximum Tsunami (PMT) are evaluated based on the maximum magnitude earthquake estimated by [1]. The established source parameters are then used to numerically model the tsunami caused by the PMT scenarios.…”

“…Therefore, it is anticipated that future tsunamis can be generated from large earthquakes along MSZ. All published articles in relation to tsunamis from the Makran fault are reviewed [1][2][3][4][5][6][7][8][9][10][11][12].…”

“…In this case, the different hazard maps result from a set of individual sources that may affect the target area. Based on available seismic information, two earthquakes, with several hundred years return period [1,9] representing worst case tsunami scenarios for Diba coasts are simulated Table 1. The impact of each individual scenario is presented in terms of maximum wave height, tsunami travel time, and maximum inundation distance.…”

Deterministic seismic hazard assessment for Sultanate of Oman

“…2 is taken from the catalogue of El-Hussain et al (2012). The initial catalogue was compiled for a spatial region spanning from 42°to 66°E and 10°to 32°N and included all events having an assigned magnitude of 3.0 and above on any magnitude scale.…”

“…They removed all duplications and applied a proper priority scheme to select the best earthquake parameters from the available catalogues. To ensure catalogue magnitude homogeneity, El-Hussain et al (2012) converted all events for which moment magnitudes were not reported into this scale.…”