Numerical Modeling of an Asteroid Impact on Earth: Matching Field Observations at the Chicxulub Crater Using the Distinct Element Method (DEM)

Abstract

In recent years, an international consortium of research organizations conducted investigations at the Chicxulub Crater in Yucatan, Mexico, to better understand the crater’s formation mechanisms and the effects produced by the impact of the asteroid that is hypothesized to have caused one of the major life extinctions on Earth. This study aims to reproduce the asteroid’s impact mechanics by matching computer simulations obtained with the use of the distinct element method (DEM) against the latest topographic data observed across the crater footprint. A 2D model was formulated using ITASCA’s PFC2D software to reproduce the asteroid’s impact on Earth. The model ground conditions prior to impact were replicated based on available geological and geophysical field information. Also, the proposed DEM model configuration was designed to reproduce a far-field effect to ascertain the energy dissipation of the asteroid’s impact at the model’s boundaries. Impact conditions of the asteroid were defined based on previous asteroid impact investigations. A parametric analysis including the asteroid’s impact angle and the asteroid’s impact velocity was conducted to assess their influence on the crater formation process. Results of the simulations included the final crater topography and stratigraphy, stress profiles, contact force chains, and velocity fields. Numerical simulations showed that both the asteroid velocity and impact inclination play a major role in the crater formation process, and that the use of DEM provides interesting insights into impact crater formation.

Keywords

• asteroid impact
• Chicxulub crater
• crater formation
• topography
• stratigraphy
• distinct element method DEM