Beyond the Original Intent — Seismic Survey Data

When a company wants to explore the ocean for potential oil or gas extraction, it needs to know what hydrocarbon is below the seafloor. To obtain this information, the company can buy seismic data for an area from a seismic survey company. Seismic surveys return information about the different layers of geology below the seafloor.A seismic survey is carried out by shooting air guns toward the seafloor from a vessel and towing an array of receivers behind the vessel to collect the returning sounds. Each layer that the sound reaches has a different density, speed of sound, and distance from the transceiver. The survey system can track the original sound, including trajectories and the time it takes to return to the transceivers, painting a picture of the sediments below the seafloor. By knowing how fast sound travels through water and how long it takes the sound to bounce off the seafloor and back to the receivers, depth can be calculated at each spot on the seafloor.The Bureau of Ocean Energy Management (BOEM) is responsible for oil and gas leasing in U.S. federal waters. Since BOEM is also responsible for issuing permits for seismic surveys, companies are required to provide copies of the data to BOEM, which uses the data to determine fair market value for lease areas and to estimate how much oil and gas is present in the Gulf of Mexico.Recently, BOEM created an extremely detailed bathymetric map of the deeper parts of the Gulf of Mexico. This map is more detailed than any other large area map of the Gulf and has the most consistent resolution of any map. BOEM geoscientists have also used the seismic survey data for the past 20 years to identify potential seafloor oil and gas seeps, mud volcanoes, coral reefs, and other “anomalous features” on the seafloor.Seismic anomalies data are found in a similar way as depth, but appear as “positive” or “negative” data beyond the normal, or background, strength of response at the seafloor surface. High positive response indicates areas where hydrocarbon seepage is slow to moderate and where limestone rock has formed, creating a substrate suitable for large, exotic organisms to settle and live. The areas of negative or very low positive response typically indicate very rapid seepage, often where mud volcanoes form.For the more detailed information, visit boem.gov/Seismic-Water-Bottom-Anomalies-Map-Gallery.

Data and Resources

Field Value
guid 925a6d9685954b4b9e4bd15994a23979
metadata_source arcgis
metadata_type geospatial
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • acoustic-amplitude
  • amerigeo
  • amerigeoss
  • anomalies
  • benthic
  • biota
  • ckan
  • corals
  • geo
  • geology
  • geoss
  • map-journal
  • marinecadastre
  • narrative
  • national
  • north-america
  • seafloor
  • seismic
  • seismic-surveys
  • story-map
  • united-states
  • water-bottom
  • water-column
isopen False
metadata_created 2025-11-21T11:06:42.330550
metadata_modified 2025-11-21T11:06:42.330555
notes When a company wants to explore the ocean for potential oil or gas extraction, it needs to know what hydrocarbon is below the seafloor. To obtain this information, the company can buy seismic data for an area from a seismic survey company. Seismic surveys return information about the different layers of geology below the seafloor.A seismic survey is carried out by shooting air guns toward the seafloor from a vessel and towing an array of receivers behind the vessel to collect the returning sounds. Each layer that the sound reaches has a different density, speed of sound, and distance from the transceiver. The survey system can track the original sound, including trajectories and the time it takes to return to the transceivers, painting a picture of the sediments below the seafloor. By knowing how fast sound travels through water and how long it takes the sound to bounce off the seafloor and back to the receivers, depth can be calculated at each spot on the seafloor.The Bureau of Ocean Energy Management (BOEM) is responsible for oil and gas leasing in U.S. federal waters. Since BOEM is also responsible for issuing permits for seismic surveys, companies are required to provide copies of the data to BOEM, which uses the data to determine fair market value for lease areas and to estimate how much oil and gas is present in the Gulf of Mexico.Recently, BOEM created an extremely detailed bathymetric map of the deeper parts of the Gulf of Mexico. This map is more detailed than any other large area map of the Gulf and has the most consistent resolution of any map. BOEM geoscientists have also used the seismic survey data for the past 20 years to identify potential seafloor oil and gas seeps, mud volcanoes, coral reefs, and other “anomalous features” on the seafloor.Seismic anomalies data are found in a similar way as depth, but appear as “positive” or “negative” data beyond the normal, or background, strength of response at the seafloor surface. High positive response indicates areas where hydrocarbon seepage is slow to moderate and where limestone rock has formed, creating a substrate suitable for large, exotic organisms to settle and live. The areas of negative or very low positive response typically indicate very rapid seepage, often where mud volcanoes form.For the more detailed information, visit boem.gov/Seismic-Water-Bottom-Anomalies-Map-Gallery.
num_resources 1
num_tags 23
title Beyond the Original Intent — Seismic Survey Data