Palmer Station, Antarctica
(2023) ·
PMSA.2022347 [5:46 · download]



Palmer Station, Antarctica. Image by Ken Keenan, courtesy of United States Antarctic Program.

This six minute recording spans 48 hours of actual ground motion at Palmer Station , a scientific research installation on Anvers Island just off the Antarctic Peninsula in West Antarctica.

Notice the steady background hiss and rumble of the Earth's microseismic background, a ubiquitous feature that can be heard worldwide. The remarkable "clicks," "pops," and "splashes" in the foreground are unique to this station, and are quite unlike the anthropogenic sounds (vehicle traffic, machinery, etc.) that frequently appear in seismic recordings made in populated areas. What are these sounds? Given the proximity of Palmer Station to the Larsen Ice Shelf and the abundance of other nearby ice features, I wonder if these may be the sounds of cryoseisms ("ice-quakes"), as icebergs grind along the ocean floor, or as ice fractures in the nearby ice sheets. It may be tempting to attribute the occasional "splashing" sound to the calving of an iceberg or to some other watery event, but, given the 500-fold speed-up of this recording, such events would have to unfold over several minutes in real Earth time. Their true origin remains a mystery to me.

On the Earthsound website you can listen to Palmer Station in near-real time.

Technical note

This recording spans 48 hours beginning on December 23, 2022 — the second day of Antarctic summer. Time-acceleration = 500; frequencies are shifted up by about 9 octaves. One second in this six-minute clip spans about 8 minutes of real Earth time. This stereo recording comes from two seismometers located in an underground borehole. The North-South ground motion is panned left, East-West is panned right.