Abstract
Numerous small (50- to 300-m-diameter) strong-backscatter objects were imaged on the 1200- to 1350-m deep crest of Vestnesa Ridge (Fram Strait) and along the 900- to 1000-m deep northeast margin of the Storegga slide valley. Ground-truthing identified most of these objects as 2- to 10-m-deep pockmarks, developed within soft, acoustically stratified silty clays (typical wet bulk density: 1400–1600 kg m-3; sound speed: 1480– 1505 m s-1; porosity, 65–75%; shear strength: 5–10 kPa; water content: 80–120%; and thermal conductivity: 0.8–0.9 W m-1 deg C-1 in the top 3 m). Gas wipeouts, enhanced reflectors, and reflector discontinuities indicate recent or ongoing activity, but the absence of local heat flow anomalies suggests that any upward fluid flows are modest and/or local.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Vogt, P., Gardner, J., Crane, K. et al. Ground-truthing 11- to 12-kHz side-scan sonar imagery in the Norwegia–Greenland Sea: Part I: Pockmarks on the Vestnesa Ridge and Storegga slide margin. Geo-Marine Letters 19, 97–110 (1999). https://doi.org/10.1007/s003670050098
Issue Date:
DOI: https://doi.org/10.1007/s003670050098