High‐resolution bathymetry of the East Pacific Rise axial summit trough 9° 49′ ‐ 51′N: A compilation of Alvin scanning sonar and altimetry data from 1991–1995

Abstract

Bathymetric data acquired during six cruises to the East Pacific Rise crest 9° 49′‐51′N are compiled into a single bathymetric database and used to create high‐resolution bathymetry maps of two geologically and biologically active areas. Scanning sonar and Alvin altimetry were collected during 23 Alvin dives to the P‐vent/Bio9 and Biomarker‐141 areas during 1991–95. Bathymetry data were filtered, edited, and processed as individual dives then combined into a single database for each cruise and statistically evaluated. Cruise data sets were numerically and visually compared and cross‐correlated to known bottom features and fixed seafloor reference markers, then horizontally shifted to establish a consistent database with 3 m vertical and 5 m horizontal resolutions. The compiled and corrected bathymetry was used to produce bathymetric maps of two areas within the axial summit collapse trough; a 2 × 104 m² area around P and Bio9 vents, and a 1.1 × 10³ m² area around Biomarker 141. The resulting detailed bathymetry maps reveal topography dominated by low‐relief volcanic constructional features and post‐eruptive collapse of lobate and sheet lava surfaces.