The spatial flux of Earth's meteorite falls found via Antarctic data

• Published in: Geology
• Main Authors: Evatt, Geoffrey, Smedley, Andrew, Joy, Katherine, Hunter, L, Tey, W H, Abrahams, L D, Gerrish, L
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2020
• Subjects: Antarc*; Antarctic; Antarctica
• Online Access: https://research.manchester.ac.uk/en/publications/d086e627-4274-4016-ab68-13d6aa1730c4; https://doi.org/10.1130/G46733.1; https://pure.manchester.ac.uk/ws/files/162954955/g46733.pdf

Contemporary calculations for the flux of extra-terrestrial material falling to the Earth’s surface (each event referred to as a ‘fall’) rely upon either short duration fireball monitoring networks or spatially limited ground-based meteorite searches. To date, making accurate fall flux estimates from the much-documented Meteorite Stranding Zones of Antarctica has been prohibited due to complicating glacial ice dynamics and difficulties in pairing together distinct meteorite samples originating from the same fall. Through glaciological analysis and use of meteorite collection data, we demonstrate how to overcome these barriers to making flux estimates. Furthermore, by showing a clear latitudinal variation in fall frequencies exists and then modelling its mathematical form, we are able to expand our Antarctic result to a global setting. In this way, we hereby provide the most accurate contemporary fall flux estimates for anywhere on Earth. Inverting the methodology provides a valuable tool for planning new meteorite collection missions to unvisited regions of Antarctica. Our modelling also enables a reassessment of the risk to Earth from larger meteoroid impacts — now 12% higher at the equator and 27% lower at the poles than if the flux were globally uniform.