May 16, 2018
Infrastructure Week: NEHRP and the Threat from Below
Posted by Annika Deurlington
Editor’s Note: During infrastructure week, AGU Public Affairs is highlighting how science helps to protect our infrastructure. Below is a re-post of a recent blog by leadership of AGU’s Seismology Section regarding current legislation to reauthorize the National Earthquake Hazards Reduction Program and improve our nation’s resiliency to seismological activity. This legislation has been introduced in the Senate by Senators Feinstein and Murkowski. AGU, in partnership with other societies like the Seismological Society of America, is encouraging members of the House to introduce and pass a companion bill.
Authorship of this guest blog is credited to: Greg Beroza (Wayne Loel Professor of Earth, Energy, and Environmental Sciences at Stanford University, AGU Seismology Section Past-President); Doug Wiens (University of Washington, St. Louis, AGU Seismology Section President); Anne Sheehan (University of Colorado, Boulder, AGU Seismology Section President-Elect); and Eliza Richardson (Pennsylvania State University, AGU Seismology Section Secretary).
The National Earthquake Hazards Reduction Program (NEHRP) was established in 1977 with the goal of reducing future earthquake losses through a better understanding of earthquakes and their effects. Mitigating earthquake losses requires establishing and enforcing engineering standards for buildings and other infrastructure, which in turn requires a scientific understanding of earthquakes sufficient to both quantify the likelihood of shaking and to anticipate its severity. The breadth of the earthquake problem spans more than a single discipline, which NEHRP explicitly recognizes through inter-agency coordination among Federal Emergency Management Agency (FEMA), National Institute of Standards and Technology (NIST), National Science Foundation (NSF), and the United States Geological Survey (USGS).
NEHRP has continued without authorization, a specific power of Congress that gives a program the legal power to exist, operate, and receive funds, since 2009. The AGU Seismology leadership is of the opinion that it is long past time for NEHRP to be reauthorized. Authorization is not an appropriation, but it is a statement of what needs to be done – in this case for the U.S. to be prepared for, and resilient to, the earthquakes that lurk in our future. The lack of reauthorization comes in a longer-term context. Since well before reauthorization lapsed – for decades now – funding for NEHRP has languished and has been deeply eroded by inflation. The predictable result is that we’re less prepared for earthquakes than we should be. The earthquake threat is real, and unlike other hazards, earthquakes strike suddenly and without warning. In a big earthquake it’s only a matter of seconds before shaking becomes violent. We need to treat the earthquake threat with the seriousness it deserves.
Perhaps not coincidentally, it has been decades since there has been a destructive urban earthquake in the U.S., and we don’t think the public is prepared for the consequences of the next bad earthquake. An important benefit of NEHRP reauthorization is that it would bring attention to the fact that a major earthquake could cause immense damage– estimated to be $200 billion in direct losses. While uncertain, this number likely underestimates losses because it does not include indirect losses (the ripple effect through the economy); nor does it include casualties, for which estimates are in the 1000s.
NEHRP is significant for earthquake monitoring and research. From a purely scientific point of view, it’s frustrating that funding is lagging because these are exciting times due to advances in sensor and communication technologies and high-performance computing. We need to take full advantage of these capabilities. Every new well-recorded earthquake has some surprising aspect, which speaks to the fact that we still have a lot to learn. Figure 1 shows the USGS estimate of seismic hazard across the United States, which provides useful context. In particular, the map highlights that:
Hazard is not just a west-coast problem. There are vast tracts of the U.S. where hazard is low, but not zero. This point was just illustrated by the November 30, 2017 M 4.1 earthquake in Delaware. Earthquakes in low-hazard areas would have disproportionate impact due to a lack of preparedness relative to more obviously earthquake-threatened areas. We don’t really understand the genesis of earthquakes in the Central and Eastern U.S., yet they put 200 million people at risk.
Parts of the map are out of date. The threat of earthquakes in Alaska is considerable, yet the Alaska map has not been updated since 2007. Hawaii is also earthquake-threatened, yet the map for Hawaii has not been updated since 1998! Puerto Rico (not shown) is currently struggling to recover from Hurricane Maria and also faces a significant earthquake threat.
The map does not reflect induced seismicity related to recent unconventional hydrocarbon development. For that the USGS developed a 1-year forecast starting in 2016. Induced earthquakes have become a problem with the potential to impact future energy options for the nation.
Figure 1. The 2014 U.S. Geological Survey (USGS) National Seismic Hazard Map displays earthquake ground motions for various probability levels across the United States and are applied in seismic provisions of building codes, insurance rate structures, risk assessments, and other public policy. The seismic hazard depicted in the above map is proportional to the peak ground acceleration with a 2% probability of being exceeded in 50 years.
This is not a partisan issue. On September 6, Senator Feinstein introduced a bill, with bi-partisan support, to reauthorize NEHRP. The threat from earthquakes is real. The seismology leadership of AGU believes it is in the strategic national interest that the effects of future earthquakes be mitigated to the extent possible, and we strongly endorse NEHRP reauthorization as a critical first step.
Those interested can find more information at:
(1) The Seismological Society of America policy statement on the reauthorization.
(2) The Earthquake Engineering Research Institute statement on the reauthorization.
(3) The USGS Advisory Committee on Earthquake Hazards Reduction (ACEHR) report. ACEHR is an external advisory committee that is charged with evaluating the effectiveness of the NEHRP program. Their report contains some great material on the value of NEHRP and its reauthorization.
(4) The AGU letter endorsing the NEHRP Reauthorization Act of 2017.
(5) Additional background material, including recent congressional testimony.