Hi Roger - i seem to be somewhat mathmatically challenged when it comes to determining how many degrees it is from one location to the next.

For instance - there was a 4.6 quake in ANDREANOF ISL, ALEUTIAN IS. following the quake south of australia - I'm trying to determine if its in the zone for FFA quakes - it appears to be close but I don't know how to determine the number of degrees difference. I can calculate mileage as the crow flies but I get lost in these degrees. Probably some geometric formula? Got any help on the subject?

Canie