At the Southern California Earthquake Center Mark communicates earthquake knowledge to the general public, decision makers, engineers, and others in order to increase earthquake awareness, reduce economic losses, and save lives. To do this Mark 1) coordinates productive interactions among SCEC scientists and with partners in science, engineering, risk management, government, business, and education; 2) manage activities that increase earthquake knowledge and science literacy at all educational levels; 3) lead efforts to improve earthquake hazard and risk assessments; and 4) promote earthquake preparedness, mitigation, and planning for response and recovery.  Many of these efforts are in coordination with members of the Earthquake Country Alliance, a statewide California private-public partnership of organizations that provide earthquake information and services, for which he is Executive Director. In this role he is the lead organizer of the Great California ShakeOut, an annual earthquake drill with millions of participants throughout the state that began in 2008.  Beginning in 2010 Mark led efforts to replicate the ShakeOut in other states and countries. Great ShakeOut Earthquake Drills now are held throughout the United States and its territories, as well as Japan, New Zealand, Canada, and elsewhere. SCEC staff and an "army" of USC students manage the websites and resources for all ShakeOut drills (except Japan). In 2014 more than 26.4 million people worldwide participated (see www.ShakeOut.org) Links www.emweekly.com www.titanhst.com www.shakeout.org www.earthquakecountry.org