Abstract
The definitive existence of a giant impact crater, two times larger than the Chixulub crater in the Yucatan peninsula, from an extraterrestrial origin, 1.6 km beneath Wilkes Land, East Antarctica, remain controversial. Here, we use the latest high-resolution gravito-topographic geopotential (SatGravRET 2014) model over Antarctica to offer a plausible confirmation of its existence. SatGravRET 2014 has a spatial resolution between 1 and 10 km at most places and included contemporary space gravimetry and gradiometry data from GRACE and GOCE, and other data including Bedmap 2 bedrock topography. We computed the gravity disturbances, the Marussi tensor of the second derivatives of the disturbing potential, the gravity invariants and their specific ratio, the strike angles and the virtual deformations to quantify the detailed geophysical features for the Wilkes Land anomaly. This set of the gravitational parameters revealed enhanced and more detailed geophysical features on the Wilkes Land Crater than previously possible only with the traditional gravity anomalies. Our findings support prior studies stating that in the Wilkes Land there is a huge impact crater/basin with detectable gravity mascon which is mostly consistent with the characteristics of an impact crater.
Highlights
The definitive existence of a giant impact crater, two times larger than the Chixulub crater in the Yucatan peninsula, from an extraterrestrial origin, 1.6 km beneath Wilkes Land, East Antarctica, remain controversial
Klokočník et al Earth, Planets and Space (2018) 70:135 various sources revealed that the structure has a diameter of some 510 km, ..., has a subglacial topography relief of ≥ 1500 m, and exhibits a negative free air gravity anomaly associated with a larger central positive free air gravity anomaly...”
We present a choice of the relevant disturbances Δg, the component Tzz of Γ, I1, I2, I, θ, vd and the bed topography; due to space reasons we cannot present all the gravity aspects
Summary
The definitive existence of a giant impact crater, two times larger than the Chixulub crater in the Yucatan peninsula, from an extraterrestrial origin, 1.6 km beneath Wilkes Land, East Antarctica, remain controversial. The Wilkes Land anomaly or mascon was first reported by von Frese et al (2006, 2009) analyzing satellite gravity data available at that time They used data from the GRACE mission (Gravity recovery and climate experiment, see, e.g., https://www.nasa.gov/mission_pages/ Grace/index.html) in spherical harmonic expansion to degree and order 90 (half-wavelength resolution on the ground ~ 200 km); they worked with gravity anomalies and the derived first vertical derivative of them to enhance the resolution and the accuracy of the Wilkes Land anomaly. The primary objective of this study is to use recently available high-resolution gravity and subglacial topography models to provide an independent assessment and to contribute positively to the hypothesis claiming that the Wilkes lowland is an impact crater (basin)
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