Global Earthquake Fatalities and Population Thomas L. Holzer a) M.EERI, and James C. Savage a) Modern global earthquake fatalities can be separated into two components: (1) fatalities from an approximately constant annual background rate that is inde- pendent of world population growth and (2) fatalities caused by earthquakes with large human death tolls, the frequency of which is dependent on world popula- tion. Earthquakes with death tolls greater than 100,000 (and 50,000) have increased with world population and obey a nonstationary Poisson distribution with rate proportional to population. We predict that the number of earthquakes with death tolls greater than 100,000 (50,000) will increase in the 21st century to 8.7Æ3.3 (20.5Æ4.3) from 4 (7) observed in the 20th century if world population reaches 10.1 billion in 2100. Combining fatalities caused by the background rate with fatalities caused by catastrophic earthquakes (>100,000 fatalities) indicates global fatalities in the 21st century will be 2.57Æ0.64 million if the average post- 1900 death toll for catastrophic earthquakes (193,000) is assumed. [DOI: 10.1193/1.4000106] INTRODUCTION From the perspective of global earthquake fatalities, the 21st century began ominously. In 2001, the M7.6 Bhuj, India, earthquake killed 20,085 people. In 2003, the M6.6 Bam, Iran, earthquake killed 31,000 people. In 2004, the M9.3 Sumatra-Andaman, Southeast Asia, earthquake killed 228,000 people, mostly by a tsunami that swept across the Indian Ocean. In 2005, the M7.6 Kashmir, Pakistan, earthquake killed 87,351 people. In 2008, the M7.9 Wenchuan, China, earthquake killed 88,287 people. And in 2010, the M7.0 Haiti earthquake killed 222,570 people. All told, approximately 699,000 people died in earth- quakes during the century’s first decade. While large losses of life in earthquakes have been observed before, the occurrence of so many very deadly earthquakes within a single decade is unprecedented. These very deadly earthquakes—along with the 2011 Tohoku, Japan, M9.0 earthquake, with its 22,626 death toll and huge financial impact—have prompted speculation that the planet is experiencing the consequences of the large urban population growth in the 20th century (e.g., Bilham 2010). (Earthquake fatalities for earthquakes reported here are described at the USGS’s world earthquake deaths Web site, http://earthquake.usgs.gov/ earthquakes/world/world_deaths.php, as of 26 April 2011. Uncertainty in the Haitian esti- mated death toll is discussed later.) The growing world population suggests that earthquakes should become increasingly deadly because the expected number of earthquake deaths is proportional to the exposed population and their vulnerability to earthquakes. This article explores the relation between Earthquake Spectra, Volume 29, No. 1, pages 155–175, February 2013; © 2012, Earthquake Engineering Research Institute a) U.S. Geological Survey, MS 977, 345 Middlefield Rd., Menlo Park, CA 94025 155