Giant submarine landslides on the Colombian margin and tsunami risk in the Caribbean Sea

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doi: 10.1016/j.epsl.2016.05.040
Author(s): Leslie, Stephen C.; Mann, Paul
Author Affiliation(s): Primary:
University of Houston, Department of Earth and Atmospheric Sciences, Houston, TX, United States
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, Vol.449, p.382-394. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 51 refs.; illus., incl. sects., sketch maps
Summary: A series of three giant, previously unrecognized submarine landslides are defined on a 16,000 line km grid of multi-channel 2D seismic reflection profiles along the active margin of northern Colombia in the western Caribbean Sea. These deposits record the collapse and mobilization of immense segments (thousands of cubic kilometers) of the submarine slope and are comparable in scale to the largest known landslides on Earth. We show that the breakaway zone for these events corresponds to the tectonically over-steepened slopes of the Magdalena Fan, an extensive submarine fan composed of sediments sourced from the northern Andes and deposited by the Magdalena River. An over-pressured zone of weakness at the base of the gas-hydrate stability layer within the fan likely facilitates slope failure. Timing of these massive slope failures is constrained by well control and occurred from the mid-to-late Pliocene to mid-Pleistocene. To understand the tsunamigenic hazards posed by the recurrence of such an event today, we model the potential tsunami source created by a submarine landslide of comparable thickness (400 m) and lateral extent (1700 km2) derived from the over-steepened upper slopes of the present day Magdalena Fan. Our modeling indicates the recurrence of an analogous slope failure would result in a major tsunami that would impact population centers along the Caribbean coastlines of Colombia, Central America, and the Greater Antilles with little advance warning.
Year of Publication: 2016
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 20 Geophysics, Applied; Active margins; Atlantic Ocean; Beata Ridge; Caribbean Sea; Cenozoic; Colombia; Colombian Basin; Continental margin; DSDP Site 153; Deep Sea Drilling Project; Gas hydrates; Geologic hazards; Geophysical profiles; Geophysical surveys; Leg 15; Leg 165; Magdalena River; Mass movements; Models; Natural hazards; Neogene; North Atlantic; ODP Site 999; Ocean Drilling Program; Pleistocene; Pliocene; Quaternary; Risk assessment; Seismic profiles; Slope stability; Slumping; South America; Submarine fans; Surveys; Tertiary; Thickness; Tsunamis; Upper Pliocene; Volume
Coordinates: N100000 N140000 W0730000 W0780000
Record ID: 2016079074
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands