Shakedown in Madagascar: Occurrence of lavakas (erosional gullies) associated with seismic activity

Abstract

Research Article| February 01, 2010 Shakedown in Madagascar: Occurrence of lavakas (erosional gullies) associated with seismic activity Rónadh Cox; Rónadh Cox 1Department of Geosciences, Williams College, Williamstown, Massachusetts 01276, USA Search for other works by this author on: GSW Google Scholar Danielle Bridgette Zentner; Danielle Bridgette Zentner 1Department of Geosciences, Williams College, Williamstown, Massachusetts 01276, USA Search for other works by this author on: GSW Google Scholar Amos Fety Michel Rakotondrazafy; Amos Fety Michel Rakotondrazafy 2Département des Sciences de La Terre, Université d'Antananarivo, Antananarivo 101, Madagascar Search for other works by this author on: GSW Google Scholar Christine Fara Rasoazanamparany Christine Fara Rasoazanamparany 1Department of Geosciences, Williams College, Williamstown, Massachusetts 01276, USA2Département des Sciences de La Terre, Université d'Antananarivo, Antananarivo 101, Madagascar Search for other works by this author on: GSW Google Scholar Author and Article Information Rónadh Cox 1Department of Geosciences, Williams College, Williamstown, Massachusetts 01276, USA Danielle Bridgette Zentner 1Department of Geosciences, Williams College, Williamstown, Massachusetts 01276, USA Amos Fety Michel Rakotondrazafy 2Département des Sciences de La Terre, Université d'Antananarivo, Antananarivo 101, Madagascar Christine Fara Rasoazanamparany 1Department of Geosciences, Williams College, Williamstown, Massachusetts 01276, USA2Département des Sciences de La Terre, Université d'Antananarivo, Antananarivo 101, Madagascar Publisher: Geological Society of America Received: 08 Sep 2009 Revision Received: 17 Sep 2009 Accepted: 18 Sep 2009 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2010 Geological Society of America Geology (2010) 38 (2): 179–182. https://doi.org/10.1130/G30670.1 Article history Received: 08 Sep 2009 Revision Received: 17 Sep 2009 Accepted: 18 Sep 2009 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Rónadh Cox, Danielle Bridgette Zentner, Amos Fety Michel Rakotondrazafy, Christine Fara Rasoazanamparany; Shakedown in Madagascar: Occurrence of lavakas (erosional gullies) associated with seismic activity. Geology 2010;; 38 (2): 179–182. doi: https://doi.org/10.1130/G30670.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Erosion via lavaka formation is widespread in Madagascar, but controls on why and where lavakas occur are not understood. Geographic information system analysis reveals a spatial correlation between lavaka abundance and the frequency of seismic events: most lavakas occur in or near areas where recorded earthquakes (magnitude 0.5–5.6) are most frequent. This correlation explains the unevenness of lavaka distribution in the Malagasy highlands, and highlights the importance of natural factors in lavaka formation. Seismic activity appears to precondition the landscape to lavaka formation, although the mechanism by which this happens is not yet known. Recognizing the connection, however, allows us to pinpoint areas prone to future lavaka development in zones of active deforestation. Areas with the greatest frequency of seismic events are most at risk for high-density lavaka development. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.