The Region of Metlaoui Facing Seismic Hazards: Study and Cartographic Approach (South Atlas of Tunisia)

The region of Metlaoui (South Atlas of Tunisia) is listed as one of the major seismotectonic zones of the national territory. About 10 major seismic events with moderate magnitude have occurred from the beginning of last century. The event of 7/11/1989 (Ms = 4.4) was undoubtedly the most important. It caused very significant material damage estimated at 224,525,000 Tunisian Dinars. This study uses a mapping tool to define areas with relatively high degrees of hazard and vulnerability. It also seeks to understand the active fault of the seismic events recorded in this region.

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Three-dimensional model of the Cascadia subduction zone using earthquake hypocenters, western Washington

Bulletin of the Seismological Society of America ◽

10.1785/bssa0820062533 ◽

1992 ◽

Vol 82 (6) ◽

pp. 2533-2548

Author(s):

Eric Rieken ◽

Richard L. Thiessen

Keyword(s):

Active Fault ◽

Three Dimensional ◽

Cascadia Subduction Zone ◽

Seismic Events ◽

Dimensional Model ◽

Three Dimensional Model ◽

Juan De Fuca ◽

Western Washington ◽

Earthquake Potential ◽

Washington Cascades

Abstract The identification of seismically active fault planes is important for assessment of earthquake potential as well as development of neotectonic models and analysis of stress systems for a region. An automated set of computer programs, SEISPLN, has been developed for the identification of three-dimensional (3-D) alignments of seismic hypocenters. The SEISPLN technique is based on rotating a 3-D elongate grid system through the hypocenter distribution. The number of events in each cell is tabulated, and those cells which contain statistically significant numbers of events are considered to be potential fault surfaces. A multiple linear regression is applied to the set of hypocenters in each delineated cell to model the 3-D geometry of each of the inferred fault surfaces. We applied the technique to earthquakes located by the Washington Regional Seismic Network to separate the seismic events associated with the subducted Juan de Fuca (JDF) plate from events in the overlying crust. A total of 259 JDF-associated events were delineated, and the resulting 3-D models of the JDF slab beneath Washington reveal a complex combination of arching and flattening. Also, a steep orientation for the slab is observed beneath the southern portion of the Washington Cascades, while a much shallower orientation is inferred beneath the northern Cascades.

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Introduction to special section: Active Fault-Related Folding: Structural Evolution, Geomorphologic Expression, Paleoseismology, and Seismic Hazards

Journal of Geophysical Research Atmospheres ◽

10.1029/2007jb004952 ◽

2007 ◽

Vol 112 (B3) ◽

Cited By ~ 8

Author(s):

James F. Dolan ◽

Jean-Philippe Avouac

Keyword(s):

Active Fault ◽

Special Section ◽

Structural Evolution ◽

Seismic Hazards

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Zagreb earthquake of 22 March 2020 – preliminary report on seismologic aspects and damage to buildings

Journal of the Croatian Association of Civil Engineers ◽

10.14256/jce.2966.2020 ◽

2020 ◽

Vol 72 (10) ◽

pp. 869-893

Keyword(s):

Seismic Activity ◽

Preliminary Report ◽

Material Damage ◽

Strong Emphasis ◽

Long Time ◽

The City ◽

Moderate Magnitude

Significant characteristics and main consequences of the 5.5 magnitude earthquake that struck Zagreb and its surroundings in the midst of the COVID-19 pandemic are presented in the paper. Although, from the seismologic aspect, the earthquake was of moderate magnitude, it caused the loss of one life and considerable material damage. An overview of the situation before the quake is given, and information about the location, seismic activity, and organisation of building inspection activity, is presented. The data on damage are roughly classified, with the focus on historic core of the city and districts situated close to the epicentre. A strong emphasis is placed on indispensable activities that should have been carried out a long time ago, in the hope that they will be prompted by this earthquake.

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