Over 530 small quakes...seismic swarms...about 20 per hour...were reported in just 2 days last week...and some residents have begun to evacuate the area.
Over 15,000 people live near the 20,000 foot/6,00 meter volcano...located 85 kms/46 miles from Arequipa.
http://www.wired.com/wiredscience/2013/02/earthquakes-and-fumaroles-as-unrest-hits-perus-sabanacaya/