TY - JOUR
T1 - Evaluation of Shipboard and Satellite-Derived Bathymetry and Gravity Data Over Seamounts in the Northwest Pacific Ocean
AU - Watts, A. B.
AU - Tozer, B.
AU - Harper, H.
AU - Boston, B.
AU - Shillington, D. J.
AU - Dunn, R.
N1 - Funding Information:
We are grateful to the officers, crew, and scientific and technical staff onboard R/V for making the acquisition of the swath bathymetry and gravity data used in this paper possible and V. Cortes Rivas, W. Fortin, H. Harper, J. Leeburn, M. Liu, and C. L. Nguyen for their help with data editing at sea. D. Sandwell (Scripp's Institution of Oceanography, USA) provided the SRTM15 + V2.0 and V28.1 global fields prior to the cruise and made a number of helpful comments on an early version of the manuscript. We thank two anonymous reviewers for their helpful comments and O. Andersen (Denmark National Space Institute) for making available the DTU15 global gravity field. This research was supported by National Science Foundation grant OCE‐1737245. Marcus G. Langseth
Publisher Copyright:
©2020. The Authors.
PY - 2020/10/1
Y1 - 2020/10/1
N2 - Earth's surface topography/bathymetry and gravity fields provide important constraints on crustal structure and the tectonic processes that act on it due, for example, to plate flexure and mantle convection. Such studies require, however, high accuracy measurements at a wide range of spatial scales. During the past few decades much progress has been made in the acquisition of bathymetry and gravity data using both shipboard and satellite altimeter methods. Surprisingly, there have been few comparisons of these data. During April–June, 2019 we had the opportunity onboard a R/V Marcus G. Langseth cruise in the northwest Pacific Ocean to compare data acquired with an EM122 Kongsberg swath bathymetry system and a refurbished Bell Aerospace BGM-3 gravimeter with the most recent global bathymetry and gravity fields. We find that while the recovery of bathymetry and gravity from satellite radar altimeter data in areas of sparse shipboard data has been impressive, root mean square discrepancies in the range 175.5–303.4 m and 2.6–6.3 mGal exist between shipboard and satellite-derived data. While these discrepancies are small, they are highly correlated and therefore have implications for the density structure, rock type and geological processes occurring on the deep seafloor. Shipboard data should continue to be acquired, especially over features such as seamounts, banks, and ridges that are associated with short wavelength (<25 km wavelength) bathymetric and gravimetric features beyond that is recoverable in satellite-derived data.
AB - Earth's surface topography/bathymetry and gravity fields provide important constraints on crustal structure and the tectonic processes that act on it due, for example, to plate flexure and mantle convection. Such studies require, however, high accuracy measurements at a wide range of spatial scales. During the past few decades much progress has been made in the acquisition of bathymetry and gravity data using both shipboard and satellite altimeter methods. Surprisingly, there have been few comparisons of these data. During April–June, 2019 we had the opportunity onboard a R/V Marcus G. Langseth cruise in the northwest Pacific Ocean to compare data acquired with an EM122 Kongsberg swath bathymetry system and a refurbished Bell Aerospace BGM-3 gravimeter with the most recent global bathymetry and gravity fields. We find that while the recovery of bathymetry and gravity from satellite radar altimeter data in areas of sparse shipboard data has been impressive, root mean square discrepancies in the range 175.5–303.4 m and 2.6–6.3 mGal exist between shipboard and satellite-derived data. While these discrepancies are small, they are highly correlated and therefore have implications for the density structure, rock type and geological processes occurring on the deep seafloor. Shipboard data should continue to be acquired, especially over features such as seamounts, banks, and ridges that are associated with short wavelength (<25 km wavelength) bathymetric and gravimetric features beyond that is recoverable in satellite-derived data.
KW - gravity anomalies and Earth structure (1219)
KW - instruments and techniques (940)
KW - marine geology and geophysics (3000)
KW - satellite geodesy (1240)
KW - seafloor morphology (3045)
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U2 - 10.1029/2020JB020396
DO - 10.1029/2020JB020396
M3 - Article
AN - SCOPUS:85093817610
SN - 2169-9313
VL - 125
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
IS - 10
M1 - e2020JB020396
ER -