ShakeResponse is a strictly informational post-earthquake prioritization tool provided by ShakeResponse LLC. After an earthquake, it uses public seismic data and standard statistical models to generate an estimated damage state for each registered property and a ranked list solely to facilitate your inspection priorities — nothing more. It does not inspect, measure, or certify any building, and it makes no guarantees other than those expressly required by applicable law.

To do that responsibly, you need to understand exactly what our alerts are, and are not.

1. ShakeResponse Is a Model, Not a Measurement

Every damage state (Green, Yellow, Orange, Red) shown in ShakeResponse is a statistical estimate, generated by applying FEMA's HAZUS fragility-curve methodology to ground-shaking intensity estimated for your site. The first estimate is predicted from the earthquake magnitude and location reported by the U.S. Geological Survey, using an intensity-prediction equation calibrated for California. For a large quake on a long fault, the first estimate measures distance from the epicenter, so it can understate shaking far along the fault until USGS publishes a ShakeMap, if it does. If USGS publishes a ShakeMap within 24 hours, we re-score from the ShakeMap's values at the grid point nearest your property. A ShakeMap blends seismic-station recordings, felt reports and models; between stations its values are estimates too. Neither is shaking measured at your site. No sensor is installed at your property, and no human has inspected your building. The output is a modeled probability of a damage category — not a direct observation of your building's actual condition. For building types without a HAZUS curve, the colour instead reflects estimated shaking measured against the alert threshold you set; it is not a damage estimate.

2. Ground Truth May Differ From the Model — Often Significantly

Actual, on-the-ground conditions at any specific building may differ materially from the model's estimate. Factors the model does not, and in many cases cannot, fully account for include:

• Site-specific soil conditions, basin effects, and local amplification;
• Liquefaction, landslide, or slope-stability hazards at your specific parcel;
• The building's actual as-built condition versus its nominal HAZUS classification (renovations, retrofits, deferred maintenance, code-era differences);
• Pre-existing or undocumented damage from prior events;
• Non-standard or mixed construction not fully captured by a single structural type code;
• Regional geology: the shaking model uses California coefficients, so estimates for properties outside California are less reliable;
• Preliminary event data: USGS magnitudes and locations are often revised after the first report. We send an updated alert when a revision or a new USGS ShakeMap version within 24 hours changes an estimate, but later revisions and ShakeMap versions are not reflected; some revisions may not produce an update, for example if the epicenter moves more than 300 km from a property or a re-check fails; and
• The inherent statistical uncertainty of ground-motion prediction and fragility modeling generally, which represents a distribution of likely outcomes, not a single guaranteed result.

In short: the model is built from general patterns across many buildings of a similar type. It reflects what is typically true — it is not a certification of what is true for your specific building.

3. No Guarantee of Accuracy or Outcome

Earthquakes are forces of nature. No one — including ShakeResponse LLC — can guarantee how the ground will shake at a given site or how a particular building will respond, and we make no such guarantee. Everything ShakeResponse provides is based on statistical models and is strictly for informational use to facilitate inspection priorities, nothing more. There are no guarantees in this Service other than those required by applicable law. Alerts may also be delayed or may not arrive at all, for example when USGS data is late or revised, or because of network, browser, device or service outages.

SHAKERESPONSE, ITS ALERTS, AND ITS MODELED DAMAGE-STATE OUTPUTS ARE PROVIDED "AS IS" AND "AS AVAILABLE," WITHOUT WARRANTY OR GUARANTEE OF ANY KIND, EXPRESS, IMPLIED, OR STATUTORY (OTHER THAN THOSE INCAPABLE OF EXCLUSION UNDER APPLICABLE LAW), INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTY OF ACCURACY, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. WE DO NOT REPRESENT, WARRANT, OR GUARANTEE THAT ANY ALERT, DAMAGE STATE, OR ESTIMATE WILL MATCH, PREDICT, OR REFLECT THE ACTUAL PHYSICAL CONDITION OF ANY BUILDING. TO THE MAXIMUM EXTENT PERMITTED BY LAW (AND SUBJECT TO THE LIMITATIONS AND STATUTORY CARVE-OUTS IN SECTION 14 OF OUR TERMS OF SERVICE, INCLUDING CALIFORNIA CIVIL CODE SECTION 1668), SHAKERESPONSE LLC AND ITS OPERATORS DISCLAIM ALL LIABILITY FOR ANY LOSS, INJURY, OR DAMAGE ARISING FROM RELIANCE ON, OR THE UNAVAILABILITY OF, ANY ALERT OR ESTIMATE.

4. Use It to Prioritize — Not to Replace Professional Judgment

ShakeResponse is a prioritization tool: after an earthquake, it helps you decide which of your properties to check on first. It is not a substitute for:

• An inspection by a licensed structural engineer or qualified building official;
• Your local jurisdiction's post-earthquake safety placarding or "yellow tag / red tag" process;
• Emergency services, if you have any reason to believe a building is unsafe or someone may be in danger;
• Official emergency alerts and earthquake early-warning systems (such as MyShake or Wireless Emergency Alerts). ShakeResponse alerts arrive after an earthquake, not before the shaking reaches you; or
• Your own visual inspection and judgment when it is safe to do so.

If a ShakeResponse alert shows Green, that does not mean your building is certified safe. If it shows Red, that does not mean it has collapsed. In every case, use the alert to decide where to look first, always confirm the situation on the ground before taking any action, and have a qualified professional confirm actual conditions before making occupancy, repair, or safety decisions.

5. Acknowledgment

By creating an account, you acknowledge that ShakeResponse is strictly an informational service to facilitate inspection priorities — nothing more — that it provides modeled estimates with no guarantees other than those required by law, that ground-truth conditions may differ materially from those estimates, and that you will confirm actual conditions on the ground before taking any action.

The Service and all outputs described on this page are provided strictly for informational purposes to facilitate inspection priorities and do not constitute engineering, inspection, safety, or legal advice.

See also: our Terms of Service and Privacy Policy.