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The Earth Institute's Lamont-Doherty Earth Observatory Earth Science
Colloquium presents "Earthquake Loss Modeling on a Global Scale: Balancing Empirical & Physics-Based Approaches," with David Wald, Geophysicist, U.S. Geological Survey, National Earthquake Information Center, Golden, CO. Open to
the public.
Earthquake Loss Modeling on a Global Scale: Balancing Empirical & Physics-Based Approaches
The USGS Prompt Assessment of Global
Earthquakes for Response (PAGER) system provides rapid and automated alerting
of estimated economic and human impacts following earthquakes around the globe.
Although PAGER's primary purpose is to quantitatively any earthquake's severity
for situational awareness and response decision-making, the underlying tools
developed are utilized for many other scientific and mitigation efforts. There
are four components of the PAGER system. First, earthquakes trigger rapid
source characterization; second, these source parameters inform our estimates
of shaking-distribution (e.g., ShakeMap). Third, losses are then modeled by
computed populations exposed per shaking intensity level, and country-specific
and shaking-dependent loss functions are used to provide estimates of economic
impact and potential casualties. Finally, these uncertain loss estimates are
communicated in an appropriate form for actionable decision-making among a
variety of users. Rapidly and automatically assessing the wide range of
seismological, demographic, building inventory, and vulnerability information
necessary to make such loss estimates entails a requisite balance of empirical
& physics-based modeling strategies. Several aspects of our problem cannot
yet be adequately solved with purely empirical, nor solely mechanistic,
approaches. The "physics-based" model components of the PAGER system
are essential for informing empirical models where they are data-limited, and
for providing a framework for better understanding the causative pathways that
dominate earthquake losses around the globe. In the course of explaining the end-to-end strategies and
science/engineering employed by the PAGER system, I also describe what
pragmatic choices were made in balancing the uncertainties in and benefits
provided by our empirical, semi-empirical, expert-opinion, and physical models.
Recognizing and reconciling the complimentary benefits of data-driven verses
theoretical problem-solving is at the core of the PAGER system, as it is for a
wide variety of other challenges within the earth sciences.
For more information on LDEO visit
www.ldeo.columbia.edu
For more information on the Earth Institute visit www.earth.columbia.edu
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