Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Seismicity trends and detachment fault structure at 13N, Mid-Atlantic Ridge

Parnell-Turner, Ross, Sohn, Robert, Peirce, Christine, Reston, Tim, MacLeod, Christopher ORCID: https://orcid.org/0000-0002-0460-1626, Searle, Roger and Simao, Nuno 2021. Seismicity trends and detachment fault structure at 13N, Mid-Atlantic Ridge. Geology 49 (3) , pp. 320-324. 10.1130/G48420.1

[thumbnail of 320.pdf]
Preview
PDF - Published Version
Available under License Creative Commons Attribution.

Download (3MB) | Preview

Abstract

At slow-spreading ridges, plate separation is commonly partly accommodated by slip on long-lived detachment faults, exposing upper mantle and lower crustal rocks on the seafloor. However, the mechanics of this process, the subsurface structure, and the interaction of these faults remain largely unknown. We report the results of a network of 56 ocean-bottom seismographs (OBSs), deployed in 2016 at the Mid-Atlantic Ridge near 13°N, that provided dense spatial coverage of two adjacent detachment faults and the intervening ridge axis. Although both detachments exhibited high levels of seismicity, they are separated by an ~8-km-wide aseismic zone, indicating that they are mechanically decoupled. A linear band of seismic activity, possibly indicating magmatism, crosscuts the 13°30′N domed detachment surface, confirming previous evidence for fault abandonment. Farther south, where the 2016 OBS network spatially overlapped with a similar survey done in 2014, significant changes in the patterns of seismicity between these surveys are observed. These changes suggest that oceanic detachments undergo previously unobserved cycles of stress accumulation and release as plate spreading is accommodated.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Earth and Environmental Sciences
Additional Information: This paper is published under the terms of the CC-BY license.
Publisher: Geological Society of America
ISSN: 0091-7613
Date of First Compliant Deposit: 8 October 2020
Date of Acceptance: 22 September 2020
Last Modified: 05 May 2023 02:22
URI: https://orca.cardiff.ac.uk/id/eprint/135338

Citation Data

Cited 5 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics