EarthRef.org Digital Archive (ERDA) -- The Global Distribution of Seamounts from Ship Depth Soundings and Satellite Altimetry

Description
Seamounts are active or extinct undersea volcanoes rising more than 1 km above the abyssal plain. They represent a significant fraction of the volcanic extrusive budget for oceanic seafloor and their distribution gives information about spatial and temporal variations in intraplate volcanic activity. In addition, they sustain important ecological communities, determine habitats for fish, and act as obstacles to currents, enhancing tidal energy dissipation and ocean mixing. In this keynote presentation for the First SBN Workshop, Dave Sandwell explains that for all these reasons, it is important to locate and characterize seamounts. Two approaches are used to map the global seamount distribution. Depth sounds from single- and multi-beam echo sounders can provide the most detailed maps with up to 200 m horizontal resolution. However, soundings from the 5600 publicly available cruises sample only a small fraction of the ocean floor. Satellite altimeter measurements of the marine gravity field can detect sea-mounts taller than about 2 km and such studies have produced seamount catalogues holding almost 15,000 seamounts . Recent retracking of the radar altimeter waveforms to improve the accuracy of the gravity field has resulted in a two-fold increase in resolution. We predict that 45,000 smaller seamounts remain uncharted. Future altimetry missions could improve on resolution and decrease noise levels even further, allowing for an even larger number of small (1-1.5 km) seamounts to be detected. Mapping the complete global distribution will help constrain the hotly-debated models of seamount formation as well as aid in understanding of marine habitats and deep ocean circulation.

Project -- Meetings and Workshops -- SBN Workshops
The goal of the Seamount Biogeosciences Network (SBN) is to bring together all the diverse science disciplines involved in seamount research, to communicate about and discuss seamount science, and to explore innovative ways to network amongst the diverse communities working on seamounts.