T6 Feedbacks between Upper-Plate Deformation, Accretion and Alteration and Plate Boundary Processes in Subduction Systems

Sunday, 10 October 2021
8:00 AM - 12:00 PM
B111

MODERN BATHYMETRIC MAPPING OF THE ALEUTIAN RIDGE (ARC) BETTER REVEALS THE SURFACE, MAGMATIC, AND STRUCTURAL PROCESSES BUILDING ITS GEOMORPHIC FORM

Paper number: T6-4
Program: Technical Sessions
Time: 8:45 AM – 9:00 AM

Authors

Abstract

INTRODUCTION: Geologically interpretable bathymetric maps of the Aleutian Ridge (Arc) were first published in the early 1950s(https://pubs.geoscienceworld.org/gsa/gsabulletin/article/64/10/1173/4522/). Beginning in the early 2000s increasingly accurate and revealing maps became available to improve deciphering of the physical and magmatic processes shaping the ridge’s geomorphic form.

NEW REGIONAL BATHYMETRIC MAP: In 2013 the Alaska Fisheries Science Center (NOAA) published an Aleutian bathymetric map based on ~2.1 million corrected, edited, and digitized soundings. The map (100 m resolution) revealed details of the regional scale volcanic and structural fabric of the entire ~1900-km length of the Alaska sector of the Aleutian Ridge (https://archive.fisheries.noaa.gov/afsc/RACE/groundfish/Bathymetry/Aleutians.htm).

NEW MULTIBEAM MAPS OF FOREARC CANYONS AND WESTERN ALEUTIAN VOLCANISM: In 2004, 2005, 2009, and 2016, various cruises created target-area maps of forearc canyons and submarine volcanoes that commonly erupt basalt, andesite, and dacite lavas and address processes of building both arc and continental crust (https://academic.oup.com/petrology/article/56/3/441/1601225) (http://dx.doi.org/10.1594/IEDA/321840).

TSUNAMI SOURCE MULTIBEAM MAPPING: Successful identification of the mechanisms that launched the destructive Alaska near- and far-field tsunamis of April 1, 1946 emphasized the need for multibeam mapping of other tsunami source areas. For example, for the Aleutian March 9, 1957 trans-Pacific tsunami, the suspected launching area of the outer Andreanof forearc (https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GL061759) (https://link.springer.com/chapter/10.10 07/978-3-319-55480-8_26).

ACQUIRING TARGET-AREA MULTIBEAM MAPS: For the remote Aleutian Ridge, acquiring target-area multibeam maps to address scientific questions is a challenging funding and operational enterprise. Through the efforts of Prof. Sang-Mook Lee of SNU, state-of-the-art (SOTA) Korean R/Vs may become available in the near future to increase opportunities for SOTA bathymetric mapping of the Aleutian Ridge (https://www.nature.com/articles/517129a).

Geological Society of America Abstracts with Programs. Vol. 53, No. 6

doi: 10.1130/abs/2021AM-365561

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