Seismic Gaps and Source Zones of Recent Large Earthquakes in Coastal Peru

abstract Seismic gaps and recurrence periods of large, shallow interplate earthquakes along the Mexican subduction zone are reexamined after combining information from a catalog of nineteenth century's earthquakes, some relocated epicenters of the early part of this century, source parameters of recent large earthquakes, and redetermined magnitudes of great, shallow earthquakes of this century. Tehuantepec and Michoacan gaps have not experienced a large shock in this century and perhaps none in the past century; they are either aseismic or have anomalously large repeat times. Guerrero, Jalisco, and Ometepec regions presently appear to have a high seismic potential. Observed average repeat times of large earthquakes (Ms ≳ 7.4) in six regions (east, central, and west Oaxaca, San Marcos, Petatlan, and Colima) are between 32 to 56 yr. Data of this century indicate that the strain is released mostly in large events (Ms ≳ 7.4). A simple dislocation model with parameters obtained from the studies of recent earthquakes explains the observed recurrence periods quite well. The b value for this zone is not meaningful, an observation which is of significance for seismic risk estimation. Most of seismic moment (or, equivalently, seismic energy) release since 1800 appears to occur for 15 yr followed by relative quiescence in the next 15 yr.

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Italy earthquake leaves seismic gaps that were last filled by three large earthquakes in 1703

10.32858/temblor.006 ◽

2016 ◽

Cited By ~ 2

Author(s):

Ross Stein ◽

Volkan Sevilgen

Keyword(s):

Seismic Gaps ◽

Large Earthquakes

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Geodetic Deformation versus Seismic Crustal Moment-Rates: Insights from the Ibero-Maghrebian Region

Remote Sensing ◽

10.3390/rs12060952 ◽

2020 ◽

Vol 12 (6) ◽

pp. 952 ◽

Cited By ~ 1

Author(s):

Federica Sparacino ◽

Mimmo Palano ◽

José Antonio Peláez ◽

José Fernández

Keyword(s):

Western Mediterranean ◽

Seismic Hazards ◽

Total Deformation ◽

Plate Convergence ◽

Seismological Data ◽

Seismogenic Source ◽

Source Zones ◽

Middle Atlas ◽

Seismic Deformation ◽

Large Earthquakes

Seismic and geodetic moment-rate comparisons can reveal regions with unexpected potential seismic hazards. We performed such a comparison for the Southeastern Iberia—Maghreb region. Located at the western Mediterranean border along the Eurasia–Nubia plate convergence, the region has been subject to a number of large earthquakes (M ≥ 6.5) in the last millennium. To this end, on the basis of available geological, tectonic, and seismological data, we divided the study area into twenty-five seismogenic source zones. Many of these seismogenic source zones, comprising the Western Betics, the Western Rif mountains, and the High, Middle, and Saharan Atlas, are characterized by seismic/geodetic ratio values lower than 23%, evidencing their prevailing aseismic behavior. Intermediate seismic/geodetic ratio values (between 35% and 60%) have been observed for some zones belonging to the Eastern Betics, the central Rif, and the Middle Atlas, indicating how crustal seismicity accounts only for a moderate fraction of the total deformation-rate budget. High seismic/geodetic ratio values (> 95%) have been observed along the Tell Atlas, highlighting a fully seismic deformation.

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