Pockmark Occurrence in the Northern Gulf of Mexico Influenced by Glacial Cycles and Hydrate Stability

On the continental slope of the northern Gulf of Mexico, pockmarks concentrate near the estimated updip edge of the hydrate stability zone (HSZ). We identified 5,691 pockmarks in the northern Gulf of Mexico by combining existing records with manually mapped pockmarks from bathymetric data. Nearly 70...

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Detalles Bibliográficos
Autores: Kumar, A., Cook, A. E., Lawal, M. A., Portnov, A., Lecours, V.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/397881
Acceso en línea:http://hdl.handle.net/10261/397881
Access Level:acceso abierto
Palabra clave:Gulf of Mexico
Hydrate dissociation
Hydrate stability zone
Last Glacial Maximum
Pockmark formation mechanisms
Pockmarks
Descripción
Sumario:On the continental slope of the northern Gulf of Mexico, pockmarks concentrate near the estimated updip edge of the hydrate stability zone (HSZ). We identified 5,691 pockmarks in the northern Gulf of Mexico by combining existing records with manually mapped pockmarks from bathymetric data. Nearly 70 percent of the pockmarks occur within 330–600 m water depth and the number of pockmarks drops abruptly at water depths >600 m. Based on hydrate stability modeling, we argue that the updip edge of the HSZ shifted downslope since the last glacial maximum. This downslope shift caused hydrate dissociation and released charged free gas resulting in pockmark formation on the seafloor. Moreover, we observe that fluctuations in the updip edge of the HSZ since the last glacial maximum (from 330 to 605 m water depth) coincide with increased pockmark abundance. On other continental margins, pockmarks have been observed within a similar water depth range, suggesting that the loss of hydrate stability during deglaciation is a worldwide phenomenon that created intense fluid emission from the seafloor.