Matt, this frequency is part of the USAF High Frequency Global Communications System (HFGCS) and those message are common. Messages are generally simulcast on 4724, 8992, 11175 and 15016.
Primary HFGCS Frequencies 24 Hours: 8992 and 11175
Back up HFGCS Frequencies Day: 13200, 15016
Back up HFGCS Frequencies Night: 4724, 6739
GEOMETRIC is in fact the call-sign of the station transmitting the message. You can expect that call-sign to change every 24 hours.
Here is an example from the 15th:
21:12Z 15 AUGUST 2021 8992.0 kHz USB (simulcast)
TO: ALL STATIONS
FM: GOAL POST
BXTALV // YN4YB UGQCM FQXNT RTSF6 NWBO
From my experience, this is the typical format:
BXTALV ( message identifier )
YN4YB UGQCM FQXNT RTSF6 ( message traffic )
NWBO ( authentication / checksum )