How can I save Thriff?

Hint 1 of 7:

Thriff may be in a cold climate, but you'll need to write yourself a searing
hot plan to save it.

Hint 2 of 7:

You need to find a way to make the Glyph of Warding that Orkan left in the
snow permanent.

Hint 3 of 7:

Orkan's journal mentions Yonking a Girgol spell on a nearby "mountain". 
(Yonk enhances magic and Girgol stops time.)

Hint 4 of 7:

That's not a mountain ... that's a volcano, full of molten rock!

Hint 5 of 7:

If you release the lava from the Girgol spell, hopefully the snow will cool
it enough so that it doesn't destroy Thriff, while still allowing you enough
time to make a new, permanent Glyph of Warding in the cooling lava.

Hint 6 of 7:

You can release the lava by using the Dispel wand/staff/etc.