A short introduction to historical earthquakes in Libya

As a result of the relative motion of the African and European plates, Libya, located at the north central margin of the African continent, has experienced a considerable intraplate tectonism, particularly in its northern coastal regions. If the seismic activity of the last fifty years, at most, is known from instrumental recording, macroseismic effects of those earthquakes which affected Libya in the past centuries are still imperfectly known. To try and partly overcome this lack of information, in this contribution we present a short introduction to historical earthquakes in Libya, focusing on the period up to 1935. According to the studies published in the last twenty years, the earliest records of earthquakes in Libya are documented in the Roman period (3rd and 4th century A.D.). There is a gap in information along the Middle and Modern Ages, while the 19th and early 20th century evidence is concentrated on effects in Tripoli, in the western part of nowadays Libya. The Hun Graben area (western part of the Gulf of Sirt) has been identified as the location of many earthquakes affecting Libya, and it is in this area that the 19 April 1935 earthquake (Mw = 7.1) struck, followed by many aftershocks. Further investigations are needed, and some hints are here given at historical sources potentially reporting on earthquake effects in Libya. Their investigation could result in the needed improvement to lay the foundations of a database and a catalogue of the historical seismicity of Libya.

Download Full-text

Historical Earthquake Scenarios for the Middle Strand of the North Anatolian Fault Deduced from Archeo-Damage Inventory and Building Deformation Modeling

Seismological Research Letters ◽

10.1785/0220200278 ◽

2020 ◽

Vol 92 (1) ◽

pp. 583-598

Author(s):

Yacine Benjelloun ◽

Julia de Sigoyer ◽

Hélène Dessales ◽

Laurent Baillet ◽

Philippe Guéguen ◽

...

Keyword(s):

Historical Earthquakes ◽

Historical Seismicity ◽

North Anatolian Fault ◽

First Century ◽

Building Vulnerability ◽

Earthquake Scenarios ◽

The North ◽

Seismicity Catalog ◽

Quality Ranking ◽

The City

Abstract The city of İznik (ancient Nicaea), located on the middle strand of the North Anatolian fault zone (MNAF), presents outstanding archeological monuments preserved from the Roman and Ottoman periods (first to fifteenth centuries A.D.), bearing deformations that can be linked to past seismic shaking. To constrain the date and intensity of these historical earthquakes, a systematic survey of earthquake archeological effects (EAEs) is carried out on the city’s damaged buildings. Each of the 235 EAEs found is given a quality ranking, and the corresponding damage is classified according to the European Macroseismic Scale 1998 (EMS-98). We show that the walls oriented north–south were preferentially damaged, and that most deformations are perpendicular to the walls’ axes. The date of postseismic repairs is constrained with available archeological data and new C14 dating of mortar charcoals. Three damage episodes are evidenced: (1) between the sixth and late eighth centuries, (2) between the nineth and late eleventh centuries A.D., and (3) after the late fourteenth century A.D. The repartition of damage as a function of building vulnerability points toward a global intensity VIII on the EMS-98. The 3D modeling of a deformed Roman obelisk shows that only earthquakes rupturing the MNAF can account for this deformation. Their magnitude can be bracketed between Mw 6 and 7. Our archeoseismological study complements the historical seismicity catalog and confirms paleoseismological data, suggesting several destructive earthquakes along the MNAF, since the first century A.D. We suggest the fault might still have accumulated enough stress to generate an Mw 7+ rupture.

Download Full-text

Recent Vs. Historical Seismicity Analysis For Banat Seismic Region (Western Part Of Romania)

Mathematical Modelling in Civil Engineering ◽

10.1515/mmce-2015-0001 ◽

2015 ◽

Vol 11 (1) ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Eugen Oros ◽

Mihai Diaconescu

Keyword(s):

Active Tectonics ◽

Historical Earthquakes ◽

Historical Seismicity ◽

Seismic Region ◽

New Information ◽

Macroseismic Effects ◽

Hazard Sources ◽

Earthquake Sequences ◽

Seismicity Analysis ◽

The City

Abstract The present day seismic activity from a region reflects the active tectonics and can confirm the seismic potential of the seismogenic sources as they are modelled using the historical seismicity. This paper makes a comparative analysis of the last decade seismicity recorded in the Banat Seismic Region (western part of Romania) and the historical seismicity of the region (Mw≥4.0). Four significant earthquake sequences have been recently localized in the region, three of them nearby the city of Timisoara (January 2012 and March 2013) and the fourth within Hateg Basin, South Carpathians (October 2013). These sequences occurred within the epicentral areas of some strong historical earthquakes (Mw≥5.0). The main events had some macroseismic effects on people up to some few kilometers from the epicenters. Our results update the Romanian earthquakes catalogue and bring new information along the local seismic hazard sources models and seismotectonics.

Download Full-text

An overview of the terrestrial invertebrates in the Victorian north central region

Proceedings of the Royal Society of Victoria ◽

10.1071/rs10019 ◽

2010 ◽

Vol 122 (2) ◽

pp. 100

Author(s):

Nick G. Collett ◽

Alan L. Yen

Keyword(s):

Central Region ◽

Environmental Changes ◽

Conservation Management ◽

North Central Region ◽

North Central ◽

Terrestrial Invertebrates ◽

The North ◽

European Settlement ◽

Lack Of Information ◽

Terrestrial Habitats

Invertebrates are the dominant faunal group in most terrestrial habitats. They play important roles, often incompletely understood, in maintaining essential ecosystem services. Despite the enormous environmental changes to the North Central Region of Victoria since European settlement, and despite the lack of information about how these changes affected the native invertebrate fauna, it is not too late to include invertebrates in the management and restoration of native habitats in the region. This paper provides an overview of our understanding about terrestrial invertebrates in the region, and provides some suggestions on how to elevate the profile and utility of invertebrates in conservation management.

Download Full-text