Earthquake Profile Options Pane

Risk: The loss-level return values are the implied aggregate damage ratio on 100-year, 250-year, and AAL losses. Use the values to identify exposures that are riskier than others. The % for the flag values is similar to a damage ratio. Touchstone creates a grid of 220-meters resolution within 5 miles of the coast, a 1-kilometer resolution within 5-10 miles of the coast, and 5-kilometers more than 10 miles off the coast. For each grid point, Touchstone stores three values: 100-year loss, 250-year loss, and AAL. It divides the losses by 1,000 so that the stored values range from 0 to 100; these are the values used during the analysis.

100-Year Loss Level

Represents the loss amount likely to be equaled or exceeded 1% of the time, or in 1 year out of 100.

Example: If the 100-year loss level is 20-25%, it means that there is a 1 percent chance in any given year that the losses are likely to exceed 20-25% of the total value.

To flag certain conditions, enter low and high loss level percentages.

250-Year Loss Level

Represents the loss amount likely to be equaled or exceeded 0.4 % of the time, or in 1 year out of 250.

Example: If the 250-year loss is 20-25%, it means that there is a 0.4 percent chance in any given year that the losses are likely to exceed 20-25% of the total value.

To flag certain conditions, enter low and high loss level percentages.

Average Annual Loss

Refers to the loss you can expect to occur per year, on average, over a period of many years.

Significant events will not happen every year; therefore, it is important to note that Average Annual Loss is a long-term expected loss.

To flag certain conditions, enter low and high loss level percentages.

Relative Risk: The % measures the percentile that location AALs are in regarding the losses for the state or county. Touchstone obtains the losses by grid within a state and county, normalized to a 200-meter resolution, and then ranks them from largest to smallest losses. The relative risk is the percentile of the grid in the state or county.

Example: A value of "50%" flags locations that are in the top half of the AALs in the state or county grid.

Relative Risk by County

The ranking of a location's risk score with respect to other locations within the same county, expressed as a percentile.

To flag certain conditions, enter low and high loss level percentages.

Relative Risk by State

The ranking of a location's risk score with respect to other locations within the same state, expressed as a percentile.

To flag certain conditions, enter low and high loss level percentages.

Earthquake Information

Distance to Nearest Fault

The distance, in miles or feet, to the nearest fault. Proximity to an active fault is an important indication of seismicity for a specific location.

To flag certain distance conditions, enter low and high distance ranges; be sure to specify units.

MMI PE (Probability of Exceedance)

The probability that at least one event of the indicated MMI (Modified Mercalli Index) intensity will occur within the next 30 years.

Return values include VI, VII, VIII, IX, X, XI, XII, with values between 0 and 100.

Example: MMI_VI indicates the likelihood that an earthquake with intensity (MMI) VI will occur in the next 30 years.

MMI RP (Intensity by Return Period)

The maximum intensity of a probable earthquake within the indicated time period.

Return values include the probable maximum intensity of an earthquake within 100-, 200-, 250, and 475-year return periods.

Example: MMI_100YR indicates the probable maximum intensity of an earthquake within a 100-year period.

Nearest Historical Earthquake

Returns the name, date and time, and magnitude of the nearest historical earthquake to a given location.

The analysis determines the most severe events by considering the top 5 events that occurred within 50 miles of the specified location, with the most severe event being the value that the analysis returns.

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California DOI Zone

The California Department of Insurance zone in which the corresponding location is found.

These zones, ranging from A1-H, are intended to assess the exposures of property insurers and reinsurers in the state of California. Generally speaking, the higher in the alphabet, the greater the risk (Zones A and B = high risk, Zones F, G, and H = less risk).

To flag certain areas, enable one or more zones in the Selection Controls selection list.

Liquefaction Likelihood

The level of liquefaction which measures a soil's susceptibility to liquefaction combined with a location's level of earthquake risk.

AIR applies standard methodologies used by the Division of Mines and Geology (DMG), United States Geological Survey (USGS), to calculate liquefaction potential. Liquefaction risk at a given site is represented by that site's potential to experience damage resulting from liquefaction. When seismic waves pass through water-saturated, loosely packed sandy soils, contact pressure between the individual grains is lost. If drainage is inadequate, what was once solid ground now behaves as a dense fluid, incapable of supporting buildings. Structures that may have survived the effects of shaking can deform, tilt or sink. This makes them unusable and unsalvageable, although they may remain structurally intact.

To flag certain liquefaction levels, enable one or more levels in the Selection Controls selection list.

Soil Type

The location's underlying soil type, which may have a determining effect on potential earthquake damage to structures. AIR uses these soil type classifications: Very Hard Rock, Hard Rock, Firm to Hard Rock, Firm Rock, Soft to Firm rock (stiff soil), Soft Rock, Stiff Clay and Sandy Soil (firm soil), Soft Soil to Firm Soil, Soft Soil (shallow soil), Soft Soil, Water.

Certain types of soils, such as soft soils, are capable of amplifying seismic waves, consequently causing more severe damage. Some types of soil, such as bay mud, sandy soil, and stiff to soft soil, are more susceptible to liquefaction. Soil is classified according to its mechanical properties. In most urban areas, mapped soil resolution varies between 25m and 100m. High-resolution soil maps are obtained from various sources, including United States Geological Survey (USGS), California Division of Mines and Geology (CDMG), and local municipalities.

To flag certain soil types, enable one or more types in the Selection Controls selection list. list.

Landslide Zone

Indicates whether the location is inside a landslide zone.

Landslide zones have a high potential for earthquake-induced slope failures, or have had landslides triggered by historical earthquake activity. Earthquake-induced landslides can cause substantial property damage. In seismic zones, areas with loose, weak soils, or areas on steep slopes are most susceptible.

Select this check box to display a notification on screen if the condition occurs.

Alquist-Priolo Fault Zone

Indicates whether the location is inside an Alquist-Priolo fault rupture zone.

Alquist-Priolo Zones are zones that surround active faults; California regulations define the zones.

Disclosure law: The California Natural Hazard Disclosure Law, effective June 1, 1998, requires sellers of property and their agents to provide buyers with a Natural Hazard Disclosure Statement if the property lies in one or more state-mapped hazard areas, including Earthquake Fault Zones. Presence of an active fault may pose a serious risk of surface rupture that may cause substantial damage to buildings located in the fault zone. The California Department of Conservation, Division of Mines and Geology Official, periodically issues maps of Alquist-Priolo zones. You can flag locations that are or are not in an Alquist-Priolo fault zone.)

Select this check box to display a notification on screen if the condition occurs.