KORE..your number 1 underground radio station

[Magical Realist]

https://mysteriousuniverse.org/2018/07/m...the-earth/

"Just this week, physicists studying cosmic rays in Antarctica have uncovered a strange radio signal that appears to have a mysterious origin. The physicists are part of the Antarctic Impulsive Transient Antenna (ANITA) program, a project which uses balloons to locate and identify signals produced by strange particles travelling from deep space as they collide with the Earth. However, this latest signal appears to originate from deep within the Earth itself. Is this a lost race of molemen and molewomen’s attempt at communication with us surface dwellers?..."

[Yazata]

The consensus seems to be neutrinos. Weird ones, not predicted by theory.

... or maybe Molemen. I like that one. (Don't suggest it to JamesR though, he'll have apoplexy.)

"Physicists have been left scratching their heads following the observation of two unusual radio signals by the balloon-borne Antarctic Impulsive Transient Antenna (ANITA). While many other signals spotted by ANITA are produced by cosmic rays crashing down through the atmosphere, the two anomalous events seem to be caused by particles travelling up through the Earth's crust. Those particles may be neutrinos but their properties seem at odds with the Standard Model of particle physics."

https://physicsworld.com/a/mysterious-ra...-neutrino/

https://arxiv.org/pdf/1803.05088.pdf