A
- Thomas J Ahrens (American, 1936–2010) – experimental methods for modeling hypervelocity impacts and materials in the Earth's core and mantle
- Tanya Atwater (American, 1942–) – plate tectonic history of North America
- Hannes Alfvén (Swedish, 1908–1995) – Alfvén waves, magnetohydrodynamics of magnetosphere; Nobel Prize in Physics
- Don L. Anderson (American, 1933–) – seismology and Earth's interior (including the Preliminary Reference Earth Model); Crafoord Prize
Read more about this topic: List Of Geophysicists