UCERF3

UCERF3 simply stands for the Uniform California Earthquake Rupture Forecast, and the third verion of it. According to the Southern California Earthquake Center UCERF3 “provides authoritative estimates of the magnitude, location, and likelihood of earthquake fault rupture throughout the state.” UCERF3 was created by a working group in 2014 and implemented in 2015.

UCERF3 is important for Earthquake Insurance because the CEA uses in its underwriting and premium calculations. Other insurers likely uses the forecasting tool as well. The forecasting method is considered the latest and best earthquake forecasting tool in the state of California. It is not the only forecasting tool at the state’s disposal.

This forecasting tool is also known as the 2015 Uniform California Earthquake Rupture Forecast, Version 3

Two Types of Scientific Models Used with Quakes:

The USGS states that: “Two kinds of scientific models are used to help safeguardagainst against earthquake losses: an Earthquake Rupture Forecast, which tells us where and when the Earth might slip along the state’s many faults, and a Ground Motion Prediction model, which estimates the subsequent shaking given one of the fault ruptures.” UCERF3 is one of the first kind, which is a rupture forecast.

To repeat the first method is an Earthquake Rupture Forecast or ERF for short. And the second is a Ground Motion Prediction model or GMP for short. UCERF3 is a type of ERF.

Why is UCERF3 is Important for Earthquake Insurance?

UCERF3 is important for quake insurance because “The California Earthquake Authority” uses “UCERF3 to evaluate insurance premiums charged to customers...” And utilizes it for “reinsurance.” Any of the factors that the CEA use in determing premium are important.

It should be noted that UCERF3 is not the only tool used in evaluating premiums. Additionally If and when UCERF3 is replaced or updated – premium changes may follow if the CEA were to change to the new model. The 2015 Uniform California Earthquake Rupture Forecast, Version 3 is exceptionally important in the world of insurance risk modeling.

How Does the Uniform California Earthquake Rupture Forecast third version, work?

UCERF3 includes about 350 fault areas. It is “a multi-disciplinary collaboration of leading experts in seismology, geology, geodesy, paleoseismology, earthquake physics, and earthquake engineering.” There were five different review panels over the course of several years. The Forecast method was partially funded by the CEA and led by the USGS, the So Cal Earthquake Center, and the California Geological Society. Using all of these various resources they created the third iteration of an Earthquake modeling tool for the state of California. The term “multi-disciplinary” simply refers to folks in different fields of expertise.

The UCERF3 essentially replaces the UCERF2. The UCERF2 used less faults and less data points and was created about 2007. The original UCERF or UCERF1 was originally from 1988 and only took a hanful of faults into consideration. Therefore the third version is much more data intensive than the first two versions.

It should be noted that UCERF3 differed from UCERF2 in some of its risk findings. Examples of this include: Findings that Greater California has a slightly lower risk of a quake in the range of 6.5 to 7.5. Greater California though has a higher risk of an earthquake greater than 7.5 than previously thought. Additional findings showed that the Los Angeles area has an increased risk of a larger earthquake compared to the rest of the state. Those are just a few of the examples.

One can imagine a newer version of UCERF3, perhaps a UCERF4 being created at some future date. It is generally believed that each updated forecast method increases in accuracy. Will a UCERF Version 4 be made?

As for the actual science and specific detailed methods used with UCERF3…we will leave that to the bureaucrats and scientists. Lots of information regarding this forecasting tool is available at USGS and other sites. Our purpose on this site is to explain enough of UCERF3 so consumers understand its place as it relates to earthquake insurance in the state of California. Since the CEA uses UCERF3 in its pricing models it is important.

How Else is UCERF3 Used?

The forecasting tool is used in all manners in and around the State of California. Not only is it used by insurers, but it is also used in building codes and building designs. Additionally the modeling tool is now used in hazard mapping. UCERF3 is considered the latest and best forecasting that science has to offer in California Earthquake risk.

Why is a Site about Earthquake Insurance Discussing in Depth Subjects such as UCERF3?

QuakeCov seeks to get in depth about Earthquake Insurance issuance. UCERF3 is indeed a pretty wonky topic in the the risk managment landscape of land movement. However since it is a tool used in “evaluat[ing] insurance premium[s]” for consumers – it is important for this site to discuss it. At some point at some future date – UCERF3 will likely give way to an updated different forecasting tool. That future tool, if and when we change will impact earthquake premiums.

The Uniform California Earthquake Rupture Forecast is an integral part of the earthquake world.

Other Sources of Information:

.scec.org/ucerf

pubs.usgs.gov/fs/2015/3009/pdf/fs2015-3009

Other sources of information were used as well.