Version History for Data Release:

Terrano, J.F., Smith, K.E.L., Muni-Morgan, A.L., and Buster, N.A., Foxen, F., 2022, Historical bathymetry in the Mississippi-Alabama coastal region: Bathymetric soundings, gridded digital elevation model, and hydrographic sheets (ver. 2.0, March 15, 2022): U.S. Geological Survey data release, https://doi.org/10.5066/P9GRUK4B.
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First posted online July 31, 2020 as Terrano, J.F., Smith, K.E.L., Muni-Morgan, A.L., and Buster, N.A., 2020, Historical bathymetry in the Mississippi-Alabama coastal region: Bathymetric soundings, gridded digital elevation model, and hydrographic sheets: U.S. Geological Survey data release, https://doi.org/10.5066/P92JEA6U.
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Revised and republished January 22, 2021

Changes from the previously published data release listed above:

1. All soundings on the h-sheets were originally digitized in feet. After publication an adjacent h-sheet was located that noted depths were also in fathoms. Upon further review and comparison with other bathymetric datasets, we determined depths deeper than 18 feet were written in fathoms on the h-sheets, though this is not noted on the h-sheets contained in this publication. The Grand_Bay_Bathymetric_Soundings.zip, Grand_Bay_Gridded_Bathymetry.zip, and associated metadata were updated accordingly to reflect feet to fathoms changes.   
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Version 2.0 revised and republished March 15, 2022

Changes in version 2.0:

1. This data release was updated to include additional h-sheets, digitized soundings, and expanded gridded bathymetry that covers from Pascagoula, Mississippi to Mobile Bay, Alabama and south to just below the barrier islands. The additional hydrograpic sheets include H00191, H00192, H00193A, H00215, H00227, H00261, H00262, H00365, H00430A, H001310, LC00018, LC00034, LC00188, LC00189 and are contained with the original h-sheets within Hydrographic_Sheets.zip. The additional soundings were added to the original shapefile within Bathymetric_Soundings.zip, and a new field was added to denote which soundings were used to create each grid. Gridded_Bathymetry.zip contains both the original Grand Bay grid and the new expanded study area grid. Please see the metadata for specific information on each file.