Tusk is 9 meters tall.
Tusk's head (the blue thing is a collar) is 50px. Someone's head is 10.75% of their full height, in this case is 967.5 cm
1px= 19.35 cm
The crater is 1087px (21033.45 cm)
It's 327px deep (6327.45 cm)
Now... for how long it is...
Second photo crater width is 28 px, which is 21033.45 cm
1 px is 751.194643 cm
Crater length is 1202px, so 902935.961 cm.
Now, a volume... 7.9464435e10 cm^3. Hooo boy. Since there are pieces flying around the "crater", I'll make a violent fragmentation and a pulverization end.
Violent Fragmentation: 69x7.9464435e10 = 5.48304602e12 Joules (Low 7-C)
Pulverization: 214.35x7.9464435e10 = 1.70332016e13 Joules (Low 7-C+)