The California parcel dataset was processed to determine whether a parcel is within an earthquake fault zone, a liquefaction zone, and/or a landslide zone. The main purpose of these data are to be used in the Earthquake Zones of Required Investigation GeoApp.

This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. In addition, a fourth feature may be included representing areas not evaluated for liquefaction or earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.

EARTHQUAKE FAULT ZONE OF REQUIRED INVESTIGATION These zones are delineated to assist cities and counties in fulfilling their responsibilities for protecting the public safety from the effects of earthquake fault rupture as required by the Alquist-Priolo Earthquake Fault Zoning Act (Public Resources Code Sections 2623 et seq). For a general description of the Alquist-Priolo Earthquake Fault Zoning Act and regulations, downloadable official zones and related information, please refer to the California Geological Survey Website at (http://www.conservation.ca.gov/cgs/rghm/ap/Pages/index.aspx) FAULT TRACES Fault trace features are from the California Geological Survey 2010 Fault Map of California and show the location of the ground surface trace of faults that are categorized by age for the past 1.6 million years (previously-defined Quaternary Period). Users of this information should be aware that active faults and earthquakes are the subject of continuing research and that refinement of the interpretations given here are sure to come within a few years. California Geological Survey Bulletin 201, “An Explanatory Text to Accompany the Geologic Map of California,” published separately, contains detailed source index maps and references to all the published and unpublished reports and information used in compiling the 1975 Fault Map of California. For additional information about the 2010 version of this map go to the following (http://www.conservation.ca.gov/cgs/cgs_history/Pages/2010_geologicmap.aspx)

LIMITATIONS 1)This site is not designed for official natural hazards disclosure determination. “Official” natural hazard zones viewed on this site are of insufficient resolution to definitively determine in all cases whether an individual property lies within a earthquake fault zone for disclosure purposes pursuant to California Civil Code Section 1103 et seq.
2)This map may not show all potentially active faults, either within the earthquake fault zones or outside their boundaries. 3)Faults shown within earthquake fault zones are the basis for establishing the zone boundaries. 4)The identification of faults and the location of fault traces are based on based on available data at various scales of accuracy, and have not been field checked. Overlay of zones on other base maps can result in discordance with base map features. 5)DISCLAIMER: The State of California and the Department of Conservation make no representations or warranties regarding the accuracy of these zones or fault traces, or the data from which these zones and fault traces were derived. Neither the State nor the Department shall be liable under any circumstances for any direct, indirect, special, incidental or consequential damages with respect to any claim by any user or any third party on account of or arising from the use of this information.

Seismic hazard zone (Alquist-Priolo) for development of the Parcel Inventory dataset for the Housing Element Site Selection (HESS) Pre-Screening Tool.

These features designate the Alquist-Priolo Earthquake Fault Zones as shown on the Official Alquist-Priolo Earthquake Fault Zones Map. The data set is comprised of polygons that form regulatory zone boundaries (Alquist-Priolo Earthquake Fault Zones). These features delineate areas where surface fault rupture previously has occurred, or where local topographic, geological, and geotechnical conditions indicate a potential for permanent ground displacements such that mitigation by avoidance as stated in Public Resources Code Section 2621.5 (https://casetext.com/statute/california-codes/california-public-resources-code/division-2-geology-mines-and-mining/chapter-75-earthquake-fault-zoning/section-26215-generally) would be required.

This data will assist cities and counties in fulfilling their responsibility to prohibit the location of developments and structures for human occupancy across the trace of active faults as required by the Alquist-Priolo Earthquake Fault Zoning Act (Public Resources Code, Division 2, Chapter 7.5, Sections 2621-2630). Local governments can withhold development permits until geologic investigations are conducted for specific sites and mitigation measures are incorporated into development plans. Sellers of property use the maps to check the location of their specific site and, if applicable, disclose to the buyer that the property lies within an earthquake fault zone as required by the Alquist-Priolo Earthquake Fault Zoning Act (PRC Section 2621.9).

For information regarding the scope and recommended methods to be used in conducting the required site investigations, see California Geological Survey (CGS) Special Publication 42, Fault-Rupture Hazard Zones in California (https://www.conservation.ca.gov/cgs/Documents/Publications/Special-Publications/SP_042.pdf).

This data was downloaded from https://maps.conservation.ca.gov/cgs/informationwarehouse/index.html.

This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.

This layer is a component of Web server for AP and SHZ zones.

This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. In addition, a fourth feature may be included representing areas not evaluated for liquefaction or earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.

© Seismic Hazards Progam, California Geological Survey, California Department of Conservation

SEISMIC HAZARD ZONES OF REQUIRED INVESTIGATION These zones are delineated to assist cities and counties in fulfilling their responsibilities for protecting the public safety from the effects of earthquake-triggered ground failure as required by the Seismic Hazards Mapping Act (Public Resources Code Sections 2690-2699.6). For general information regarding the designation of seismic hazard zones, see California Geological Survey Special Publication 118, Recommended Criteria for Delineating Seismic Hazard Zones in California. For information regarding the scope and recommended methods to be used in conducting the required site investigations, see California Geological Survey Special Publication 117A, Guidelines for Evaluating and Mitigating Seismic Hazards in California. For a general description of the Seismic Hazards Zonation Program, the Seismic Hazards Mapping Act and regulations, downloadable official zones and related information, please refer to the California Geological Survey Website at http://www.conservation.ca.gov/cgs/shzp/.
LIMITATIONS 1) This site is not designed for official natural hazards disclosure determination. “Official” natural hazard zones viewed on this site have been modified for display purposes, and are of insufficient resolution to definitively determine in all cases whether an individual property lies within a seismic hazard zone for disclosure purposes pursuant to California Civil Code Section 1103 et seq.
2) These zones may not include all areas that have the potential for liquefaction, landsliding, strong earthquake ground shaking or other earthquake and geologic hazards. Also, a single earthquake capable of causing liquefaction or triggering landslide failure will not uniformly affect the entire area zoned. 3) Delineation of official seismic hazard zones was done in accordance with U.S. Geological Survey 1:24,000 base map standards which provides that 90 percent of cultural features be located within 40 feet (horizontal accuracy). Overlay of zones on other base maps can result in discordance with base map features. 4) DISCLAIMER: The State of California and the Department of Conservation make no representations or warranties regarding the accuracy of these zones, or the data from which these zones were derived. Neither the State nor the Department shall be liable under any circumstances for any direct, indirect, special, incidental or consequential damages with respect to any claim by any user or any third party on account of or arising from the use of this information.

Note: The DOC hosted version will be maintained through 2022, but is being retired in favor of an ArcGIS Online Hosted version of the same data. Those data can be found at: https://cadoc.maps.arcgis.com/home/item.html?id=921a7c243d074fa081af2b9d19be0315This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. In addition, a fourth feature may be included representing areas not evaluated for liquefaction or earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.

This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. In addition, a fourth feature may be included representing areas not evaluated for liquefaction or earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.

Abstract:This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. In addition, a fourth feature may be included representing areas not evaluated for liquefaction or earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.Purpose:The map is used by cities and counties to regulate development and by property owners selling property within areas where seismic hazard zones have been identified. Local governments can withhold development permits until geologic or soils investigations are conducted for specific sites and mitigation measures are incorporated into development plans. Sellers of property use the maps to check the location of their specific site and, if applicable, disclose to the buyer that the property lies within a seismic hazard zone as required by the Seismic Hazards Mapping Act of 1990 (Public Resources Code, Division 2, Chapter 7.8). For information regarding the scope and recommended methods to be used in conducting the required site investigations, see California Geological Survey Special Publication 117A, Guidelines for Evaluating and Mitigating Seismic Hazards in California.Supplemental Information:This map may not show all areas that have potential for liquefaction or landsliding. Also, a single earthquake capable of causing liquefaction or triggering landslide failure will not uniformly affect the entire area zoned. The identification and location of liquefaction and earthquake-induced landslide zones are based on the best available data. However, the quality of data used is varied. Zone boundaries have been drawn as accurately as possible at the map scale.Full detail of metadataReferenced from external source.

This dataset contains the seismic site-response zonation map for the Netherlands. The site-response (amplification) zonation map for the Netherlands is designed by transforming geological 3D grid cell models into five classes and an amplification factor (AF) is assigned to most of the classes. This site-response assessment, presented on a nationwide scale is important for a first identification of regions with increased seismic hazard potential, for example at locations with mining or geothermal energy activities. The site-response zonation map enables a prediction of site-response after a local earthquake as recommended in the following. It is very important to note that lithological information from geological voxel models is based on spatial interpolation and aimed at interpretations on regional scale. As a consequence, the presented site-response zonation map is also designed for regional interpretation, and not on individual grid cell scale. Furthermore, at locations with large subsurface heterogeneity, the interpretation should be handled with care. Additional local investigations measurements should be performed at sites of interest in order to assess the site-response in detail. For the map presented, the uncertainties to keep in mind are: first, the AF distribution along the classes, and secondly the uncertainty of the geological model used. The AF is designed to be added to an input seismic signal at a reference horizon with a shear-wave velocity of 500 m/s. This AF is class-dependent and covering only frequencies of 1-10 Hz. Furthermore, the AF does not reflect the maximum amplification that might occur within a smaller frequency band. Moreover, in the country's southern regions, a topographic effect may influence the site-response. It is important to mention that for now these areas are aggregated in Class V and require additional detailed site investigations for site-response assessment. The zonation map is based on digital geological models DGM, NL3D and GeoTOP (www.dinoloket.nl/subsurface-models) resampled to a regular grid (100m by 100m). The AF and associated uncertainty per class are available from the NetCDF metadata.

County Faults/Fault Zones (Per Riverside County General Plan 10/2003). Alquist-Priolo Earthquake Fault Zones have been designated by the California Division of Mines and Geology for the Elsinore, San Jacinto, and San Andreas fault zones in Riverside County. Within the rapidly growing county, State A-P mapping has not kept pace with development. The County of Riverside has zoned fault systems and required similar special studies prior to development. These are referred to as County Fault Zones on Figure S-2 and in the Technical Background Report. Within A-P and County Fault Zones, proposed tracts of four or more dwelling units must investigate the potential for and setback from ground rupture hazards. As there are many active faults in Riverside County, with new fault strands being continually discovered, all proposed structures designed for human occupancy should be required to investigate the potential for and setback from ground rupture. Also of concern are structures, not for human occupancy, that can cause harm if damaged by an earthquake, such as utility, communications, and transportation lifelines. The County regulates most development projects within earthquake fault zones (Figure S-2). Projects include all land divisions and most structures for human occupancy. Before a project can be permitted within an A-P Earthquake Fault Zone, County Fault Zone, or within 150 feet of any other potentially active or active fault mapped in published United States Geological Survey (USGS) or California Division of Mining and Geology (CDMG) reports, a geologic investigation must demonstrate that proposed buildings will not be constructed across active faults.Updated 2/2016 with Thermal and Indio California Geologic Survey Quads

© USGS, California Division of Mining and Geology

This layer is a component of NaturalFeaturesAndHazards.

Analysis of ‘CGS Seismic Hazards Program: Liquefaction Zones’ provided by Analyst-2 (analyst-2.ai), based on source dataset retrieved from https://catalog.data.gov/dataset/7d92db95-029c-4550-bf3d-7d6cf0e3ee30 on 27 January 2022.

--- Dataset description provided by original source is as follows ---

--- Original source retains full ownership of the source dataset ---

Analysis of ‘CGS Seismic Hazards Program: Landslide Zones (DOC Hosted)’ provided by Analyst-2 (analyst-2.ai), based on source dataset retrieved from https://catalog.data.gov/dataset/a91091ac-e957-46ed-b7c3-9c2cfb391e04 on 12 February 2022.

--- Dataset description provided by original source is as follows ---

This is a digital Seismic Hazard Zone Map presenting areas where liquefaction and landslides may occur during a strong earthquake. Three types of geological hazards, referred to as seismic hazard zones, may be featured on the map: 1) liquefaction, 2) earthquake-induced landslides, and 3) overlapping liquefaction and earthquake-induced landslides. In addition, a fourth feature may be included representing areas not evaluated for liquefaction or earthquake-induced landslides. Developers of properties falling within any of the three zones may be required to investigate the potential hazard and mitigate its threat during the local permitting process.

--- Original source retains full ownership of the source dataset ---

Earthquakes represent a serious threat to the people and institutions of Afghanistan. As part of a United States Agency for International Development (USAID) effort to assess the resource potential and seismic hazards of Afghanistan, the Seismic Hazard Mapping group of the United States Geological Survey (USGS) has prepared a series of probabilistic seismic hazard maps that help quantify the expected frequency and strength of ground shaking nationwide. To construct the maps, we do a complete hazard analysis for each of ~35,000 sites in the study area. We use a probabilistic methodology that accounts for all potential seismic sources and their rates of earthquake activity, and we incorporate modeling uncertainty by using logic trees for source and ground-motion parameters. See the Appendix for an explanation of probabilistic seismic hazard analysis and discussion of seismic risk. Production of the seismic hazard maps is challenging because the geological and seismological data required to produce a seismic hazard model are limited. The data that are available for this project include historical seismicity and poorly constrained slip rates on only a few of the many active faults in the country. Much of the hazard is derived from a new catalog of historical earthquakes: from 1964 to the present, with magnitude equal to or greater than about 4.5, and with depth between 0 and 250 kilometers. We also include four specific faults in the model: the Chaman fault with an assigned slip rate of 10 mm/yr, the Central Badakhshan fault with an assigned slip rate of 12 mm/yr, the Darvaz fault with an assigned slip rate of 7 mm/yr, and the Hari Rud fault with an assigned slip rate of 2 mm/yr. For these faults and for shallow seismicity less than 50 km deep, we incorporate published ground-motion estimates from tectonically active regions of western North America, Europe, and the Middle East. Ground-motion estimates for deeper seismicity are derived from data in subduction environments. We apply estimates derived for tectonic regions where subduction is the main tectonic process for intermediate-depth seismicity between 50- and 250-km depth. Within the framework of these limitations, we have developed a preliminary probabilistic seismic-hazard assessment of Afghanistan, the type of analysis that underpins the seismic components of modern building codes in the United States. The assessment includes maps of estimated peak ground-acceleration (PGA), 0.2-second spectral acceleration (SA), and 1.0-second SA, with return periods of about 500 years (equal to a 10-percent probability in 50 years), 1000 years (equal to a 5-percent probability in 50 years), and 2,500 years (equal to a 2-percent probability in 50 years)

An earthquake of magnitude 6.0-6.5 in the Sydney region of Australia is viewed by the global insurance community as one of the top 40 risks it faces worldwide from natural disasters . The high ranking of this perceived risk is due to the high population density, standards of construction and the level of insurance exposure in Sydney. Consequently, earthquake hazard and risk in Sydney is an important issue, and one that requires a focused and detailed study in order for the implications of such an earthquake to be fully understood. The presence of regolith (soils, sediments and weathered rock) can dramatically affect the level of ground shaking experienced during an earthquake. The relatively soft materials that constitute regolith tend to have low seismic velocities that amplify ground shaking during an earthquake, increasing the potential for damage to buildings and other infrastructure in the affected area. Therefore, models of the response of regolith to an earthquake (referred to as site response) form an integral part of any earthquake risk assessment. This report documents a preliminary study of potential ground motion amplification due to the regolith in the Botany area of Sydney, Australia. Botany was chosen due to the presence of a significant thickness of regolith and a high value and concentration of critical infrastructure. This report is intended to highlight the potential for significant levels of amplification within the study area, and draw attention to the need for more work on assessing the actual earthquake risk faced by the Sydney region. In order to determine the amount of ground motion amplification that could be seen in the Botany area, the regolith was classified into a series of four site classes. These regolith site classes are differentiated in terms of geotechnical properties that control ground shaking potential. This classification was based upon published and unpublished geotechnical data as well as seismic velocities obtained by Geoscience Australia. Once geotechnical models were defined for each regolith site class, amplification factors were calculated using a vertically propagating shear wave model. This model accounts for the softening and critical damping of the regolith column during large earthquakes. The results demonstrate that there is significant potential for amplification of ground shaking within the study area. For example, the site class that covers the vast majority of the study area has a maximum amplification factor greater than 3.0 at a fundamental site period of approximately 0.5 s. This period of motion would be expected to strongly affect the structures in the study area. The modelled amplification factors suggest that, should an earthquake impact the area, the potential for high levels of ground shaking would be dramatically increased due to the properties of the local regolith. An earthquake similar to the event experienced in Newcastle in 1989 was simulated, in order to demonstrate the potential amplification effect of the regolith during an earthquake. Whilst this simulation is in no way a full probabilistic risk analysis of the area, it does demonstrate that the amplification of ground shaking could cause response spectral accelerations in excess of 1.0 g, at periods of vibration that would be expected to cause damage to structures in the area. It is important to emphasise that this work is intended to provide a point of focus to initiate discussion rather than be a definitive seismic hazard assessment product. The results have been derived with limited geotechnical data, and without a detailed analysis of the uncertainties present within either the data or the modelling process. Nevertheless, this work does provide a starting point for recognising and addressing the potential risk that earthquakes pose to the study area.

This dataset contains input and output files used to run the RSQSim earthquake simulations performed in our study: Herrero‐Barbero, P., Álvarez‐Gómez, J. A., Williams, C., Villamor, P., Insua‐Arévalo, J. M., Alonso‐Henar, J., & Martínez‐Díaz, J. J. Physics‐based earthquake simulations in slow‐moving faults: a case study from the Eastern Betic Shear Zone (SE Iberian Peninsula). Journal of Geophysical Research: Solid Earth, e2020JB021133. https://doi.org/10.1029/2020JB021133