The fractional increase in temperature that will cause so much harm to so many creatures
(including humans) is totally insignificant so the idea that this extra heat will (a) penetrate
and (b) influence the heat balance of the planet is a complete non-starter. It is not just a
surface effect but a "tiny, tiny sliver of the surface" effect and so neither competes with
nor affects the massive energy flows within the planet proper - certainly not down to the
mantle.

The forces behind earthquakes of this nature (pardon the pun) are phenomenally large,
truly hard to understand in human terms. The energies contained, transmitted and released
by earth engine events (volcanoes, earthquakes, tectonics in general) are almost impossible
to comprehend unless you've spent some time looking into that field.

However, when a bullet is fired from a gun, the energy transmitted in that last fraction of
an inch of trigger movement is totally out of proportion to the energy released to project
the bullet - the indirect effect of tiny changes can indeed have large & widespread impacts.
(One could make the analogy with the last ounce of pressure on the trigger of a handgun in
Sarajevo and the resulting years of World War I - "the bullet that killed 16 million people".)

A small reduction in ice thickness over a large area means that a significant weight has
been removed during a blink of geological time. The rebound of that section of the crust
due to the rapid change in forces upon it affects the adjoining crust and any faults now
have also had a change of the forces previously locking them in place.

Added to this, there are two other effects: the "ripple" of change that spreads out,
weakening all of the time but still potentially (and historically proven) powerful enough
to affect any contacted "trigger point" in order to effectively propagate the event; and
the "ringing" effect where the shock from a major earth event (volcano, earthquake)
reverberates around the planet (i.e., not just to adjoining areas but through deeper
transmission paths).

Whether these changes are sufficient to release (cause) earthquakes in a *particular* case
is beyond our ability to accurately determine but in practice, it can and it does have this
capability in general so yes, the ongoing rush to the cliff of Chaos is even having effects
of a far greater nature than "just a change in temperature".

That doesn't mean that *this* earthquake was "caused" (or even "triggered" by human
activity but, as the scale of the impact continues to increase, the frequency & scale of
earthquakes *will* be affected thanks to "Business As Usual" winning out.