If it is Mount Rainier you should hear something about it...Cascades volcano observatory? If these are normal earthquakes (double couple) you might expect to see the P wave arrival and the S wave arrival, and the difference in time give you the distance....but I have trouble seeing these arrivals on that link (it is not really what I do). This could be because they are local...close to Rainier...or else I am just not seeing the P and S arrivals....Chris