[zakary]

Can you explain what uses room temp squids and JJ’s would have for magnetotelluric geophysics?

[defrost]

Better cheaper faster ultrahigh magnetic sensing of magnetic flux and field across a broad dynamic range.

Typical setups are networked fields of multiple axis sub nanotesla magnetic sensors with processing to reduce noise and subtract interference in order to extract a differential change across time and space to convert to a deep earth image.

You know, the usual stuff.

The essential principal is a fixed sensor (network) that records the diurnal (daily) magnetic flux and specifically locals for local 'drag' caused by local features (deep metal deposits, more generally volumes with varying magnetic properties).

[fghorow]

Not to mention no more HUGE and HEAVY field coils to lug around and bury...

[defrost]

You carry stuff ?!!?

Get a plane: https://www.magspec.com.au/about-magspec

STOL crop dusters are fun: https://www.youtube.com/watch?v=1_MO5Wfomks

[fghorow]

Planes are great for high frequency signals, granted.

Deep stuff requires much longer frequencies.

[defrost]

True - I've done both over the years, in the field and coding geophysical aquisition aquisition, processing, visualisation, and interpretation.

Still hard to pass up a chance to pile on the downsides of the slog work :)