L-11-11-BS MCS

Dataset zip file

Download (6.4 GB)

View Contents

Navigation File

Download (22.5 MB)

Seismic Metadata v.1

Download

View Metadata

Data Type

2D Multichannel Seismic

Data Acquisition System

Bolt Airgun and Sentry Solid Streamer

Contributor

U.S. Geological Survey

Dates

Started on Aug. 6, 2011, and ended on Sept. 1, 2011.

Number of Tracklines

18

Distance Shot

2,052 km

Description

In 2011, the U.S. Geological Survey (USGS) conducted a 2D MCS survey in support of U.S. extended continental shelf (ECS) assessments in the Bering Sea. The survey was conducted with the R/V Marcus G. Langseth, a geophysical research vessel owned by the National Science Foundation and operated by Lamont-Doherty Earth Observatory of Columbia University.

Purpose

This field survey were designed to determine sediment thickness and acoustic velocity in support of extended continental shelf maritime zone definition, conducted on behalf of the interagency U.S. Extended Continental Shelf Project, and are being released without restriction or warranty.

Other Survey Identifiers

MGL1111 was used by Lamont-Doherty Earth Observatory.

Geographic Features

Bering Sea

Processed Methods

Seismic Reflection

Processed Data Classes

Migration, Stack

Data File Formats

SEG-Y

Embedded Navigation

Yes

Data Class

Processed

Seismic Data Provenances

Digitally Acquired Digital SEG

Data Media

Online

Data Quality

The quality of the MCS data was excellent on the cruise. No major problems occurred with the seismic system. The airguns were powered down 6 times during L-11-11-BS but these power-downs introduced no significant data gaps. Most power-downs lasted 30 minutes or less. In these cases, with an 8 km streamer, the fold was reduced but no gap in the profile section resulted. During the survey, some variability in gun array volume and streamer depth occurred due to weather and maintenance requirements. This is documented in the observer logs for each acquisition line.

Processing

Field data were recorded in demultiplexed SEG-D format. Upon completion of an MCS profile line, SEG-D data files (one per shot) were posted to the ship’s server. These were concatenated into a single SEG-D file and imported to Paradigm’s Focus software for processing. Products of shipboard processing included raw shot gathers, CDP gathers processed through gapped predictive deconvolution, preliminary unmigrated stacked sections, post-stack FK-migrated sections, and stacking velocity fields. All MCS processing was reviewed and finalized post-cruise.

Datum

World Geodetic System 1984 (WGS84)