Person: Llanes Estrada, María Pilar
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First Name
María Pilar
Last Name
Llanes Estrada
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Geodinámica Interna
Identifiers
2 results
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Item Submarine landslide deposits of the historical lateral collapse of Ritter Island, Papua New Guinea(Marine and Petroleum Geology, 2015) Day, Simon; Llanes Estrada, María Pilar; Silver, Eli; Hoffmann, Gary; Ward, Steve; Driscol, NealThe March 13th 1888 collapse of Ritter Island in Papua New Guinea is the largest known sector collapse of an island volcano in historical times. One single event removed most of the island and its western submarine flank, and produced a landslide deposit that extends at least 70 km from the headwall of the collapse scar. We have mapped and described the deposits of the debris avalanche left by the collapse using full-coverage multibeam bathymetry, side-scan sonar backscatter intensity mapping, chirp seismic-reflection profiles, TowCam photographs of the seafloor and samples from a single dredge. Applying concepts originally developed on the 1980 Mount St. Helens collapse landslide deposits, we find that the Ritter landslide deposits show three distinct morphological facies: large block debris avalanche, matrix-rich debris avalanche and distal debris flow facies. Restoring the island's land and submarine topography we obtained a volume of 4.2 km3 for the initial collapse, about 75% of which is now forming the large block facies at distances less than 12 km from the collapse scar. The matrix-rich facies volume is unknown, but large scale erosion of the marine sediment substrate yielded a minimum total volume of 6.4 km3 in the distal debris flow and/or turbidite deposits, highlighting the efficiency of substrate erosion during the later history of the landslide movement. Although studying submarine landslide deposits we can never have the same confidence that subaerial observations provide, our analysis shows that well-exposed submarine landslide deposits can be interpreted in a similar way to subaerial volcano collapse deposits, and that they can in turn be used to interpret older, incompletely exposed submarine landslide deposits. Studying the deposits from a facies perspective provides the basis for reconstructing the kinematics of a collapse event landslide; understanding the mechanisms involved in its movement and deposition; and so providing key inputs to tsunami models.Item New Survey Explores the Northern Hispaniola Offshore Margin(2015) Carbo Gorosabel, Andrés; Granja Bruña, José Luis; Rodríguez Zurrunero, Álvaro; Muñoz Martín, Alfonso; Gorosabel Araus, J.M.; Llanes Estrada, María Pilar; Druet Vélez, MaríaThe highly oblique convergence between the North American and Caribbean plates has yielded that the thickened crust of Bahamas banks impinges into northern Hispaniola developing a narrow band of compressive deformation (northern Hispaniola margin) and a thick foreland basin (Hispaniola-Caicos basin). Approximately 280 km of 2D MCS profiles and 17000 km2 of high-resolution, systematic swath bathymetry data were recorded in the northern Hispaniola offshore margin in November-December of 2013 (NORCARIBE cruise). This is the first time that this region is explored systematically with highresolution multibeam bathymetry. Using new multibeam bathymetry and MCS data, combined we have studied the along- and across-strike variations of the shallower structure along a 330 km-long segment of the northern Hispaniola margin. Pronounced along-strike changes in structural style observed in the northern Hispaniola margin and Hispaniola-Caicos basin are associated with the active oblique underthrusting/indentation of the irregular boundary of the southernmost slope of the Mouchouir and Silver banks. The upper slope of the northern Hispaniola margin exhibits good economic potential associated to thick slope basins and terraces where is observable a continuous and prominent BSR. Preliminary results provide well- defined targets to carry out future exploration studies.