Data-driven insights into correlation among geophysical setting, topography and seafloor sediments in the Ross Sea, Antarctic

Polina Lemenkova

doi:10.5752/p.2318-2962.2021v31n64p1

Abstract

Detailed mapping based on the high-resolution grids, such as GEBCO, ETOPO1, GlobSed, EGM-2008 is crucial for various domains of Earth sciences: geophysics, glaciology, Quaternary, sedimentology, geology, environmental science, geomorphology, etc. The study presented a GMT-based scripting techniques of the cartographic data processing aimed at the comparative analysis of the bathymetry, sediment thickness, geologic objects and geophysical settings in the study area based on various datasets. The study area is located in the Ross Sea, Antarctic. The highest values of the sediment thickness over 7,500 m are dominating in the southwest segment of the Ross Sea closer to the Victoria Land, followed by the region over the Ross Ice Shelf with values between 5,500 to 7,000 m (170°-175°W). The increased sediment thickness (2,500 to 3,000 m) was also mapped seen in the region NE off the Sulzberger Bay (70-75°S to 140-155°W), caused by the closeness of the Marie Bird Land ice coasts. A remarkable correlation between the gravity and the topography of the sea-land border in the Marie Bird Land area is well reflected in the coastal line and a set of the higher values in the free-air gravity. On the contrary, negative values (–60 to -80 mGal) are notable along the submarine toughs stretching parallel in the western part of the basin: e.g. the trough stretching in NW-SE direction in the 170°W-175°E, 65°S-68°S, between the 167°W-175°W, 70°S-72°S. Such correlations are clearly visible on the map, indicating geological lineaments and bathymetric depressions correlating with gravity grids. The paper contributes to the regional studies of the Ross Sea, the Antarctic and Polar region, and development of the cartographic technical methodologies by presenting an application of the GMT for thematic mapping.

Highlights

The study presents an analysis of the geophysical and topographic settings of the Ross Sea, a marginal Sea of the Antarctic located between the Victoria Land and Marie Byrd Land, within the Ross Embayment
There are six resulting maps plotted on the Generic Mapping Tools (GMT) basis covering the area of the Ross Sea: Figure 1 showing the circumpolar map of the Antarctic region in 1:60,000,000 scale showing the location of the Ross Sea and the Weddell Sea; Figure 2 showing the bathymetry extent of the Ross Sea; Figure 3 showing the tectonic settings and the geological lineaments over the study area; Figure 4 shows the distribution of the sediment thickness in the Ross Sea basin; Figure 5 and figure 6 showing the geophysical settings of the study area
The analysis of GEBCO grid (Figure 2) shows that the bathymetry of the Ross Sea is generally shallow with around one-third of the sea to be shallower than 500 m, about less than a half has the values between the 500 and 100 m

Summary

Introduction

The study presents an analysis of the geophysical and topographic settings of the Ross Sea, a marginal Sea of the Antarctic located between the Victoria Land and Marie Byrd Land, within the Ross Embayment. Despite the variety of research on Antarctica as a continent, there is relatively little research on the Ross Sea of the concept of sediments and relations between the geologic and bathymetric settings and sediment thickness on the seafloor. The focus of scientific research on Antarctic research has been increasing rapidly along with ongoing expeditions and collected data, the complex comparative analysis of the geophysical, geological and bathymetric settings of the Ross Sea basin still insufficient, creating needs in the creating of a series of the thematic maps of the Ross Sea. Determination of the importance of geological and glaciological conditions of the South Pole as well as submarine geomorphology of the Ross Sea is relevant to the analysis of the sediment distribution over the seafloor of its basin. Cartographic visualization of these parameters provides an opportunity to analyses impacts to variation in sediment thickness by identifying factors and directions of the sediment inflow with regards to the terrain relief and bathymetry

Methods

Results

Discussion

Conclusion