English

The Zhamanshin Impact Event: Potential Implications for Environmental Responses and Biological Linkages on Earth and Beyond

Earth and Planetary Astrophysics 2026-04-07 v1

Abstract

At least one large-body (diameter > 1.1 km) hypervelocity cratering event occurred during ~ 0.8-0.90 Ma (Zhamanshin, Kazakhstan) in the Middle Pleistocene Transition period. Analysis designed to reduce uncertainty in the dimensions of the Zhamanshin structure employing high resolution topography demonstrated that it likely generated a ~ 26.5 km diameter multi-ring crater. This is at least two times larger than the current best estimates. Using a range of accepted impactor sizes, velocities, compositions, and angles of impact, such impacts typically yield kinetic energies of impact over 240,000 Megatons (TNT). Explosive energetic events of this magnitude (e.g., Yellowstone Caldera) at other times (K-Pg) have created global environmental effects. The factor of two discrepancy in the dimensions of Zhamanshin increases the kinetic energy yield by factors of 7-10, with significantly larger environmental consequences. This justifies examination of rapid climate transitions linked to biological consequences, including those related to environmental perturbations, at ~0.9 Ma.

Keywords

Cite

@article{arxiv.2604.04884,
  title  = {The Zhamanshin Impact Event: Potential Implications for Environmental Responses and Biological Linkages on Earth and Beyond},
  author = {James B. Garvin and Connor J. Anderson and Katherine A. Melocik and Devin R. McClain and Scott S. Sinno and Myoung-Jong Noh and Compton J. Tucker},
  journal= {arXiv preprint arXiv:2604.04884},
  year   = {2026}
}

Comments

Submitted to Planetary Science Journal