![download usgs map for a region download usgs map for a region](https://geoinfo.nmt.edu/publications/maps/topographic/strawberrypeak.png)
The online USGS Store is the only site for ordering paper topographic maps.
#Download usgs map for a region download
The National Map Download Clien t - Download free digital Historical topographic maps (GeoPDF and GeoTIFF formats) and US Topos. This is the only USGS site for ordering paper maps. Map Locator on the USGS Store - Search and download free digital maps in GeoPDF format or order paper maps. Download free digital maps in GeoPDF, GeoTIFF, JPG, and KMZ formats. TopoView - The largest selection of digital options. Most applications have an option for toggling on map indices showing an outline of all the maps, though you must zoom in to see the lines: This includes both current US Topo maps (computer generated every 3 years since 2009) and Historical topographic maps (produced by hand until 2009). The best known USGS maps are the 1:24,000-scale topographic maps, also known as 7.5-minute quadrangles.ĭownload all dates and scales of USGS topographic maps free of charge from the following applications or order paper copies of all dates through the USGS Store. Geological Survey (USGS) has been the primary civilian mapping agency of the United States since 1879. Many of the region’s utilities and lifeline owners have made use of an earlier version of these maps in vulnerability assessments of their systems.The U.S. Geological Survey, and the California Geological Survey. These maps are the result of over a decade of work and collaboration between geologists from the consulting firm William Lettis & Associates, the U.S. The new maps show in unprecedented detail the nature of the materials that underlie areas of densest urban development and highlight areas that may be prone to shaking-related damage during future earthquakes. Bay mud remains a seismic hazard because on the basis of its past performance in earthquakes it will produce stronger levels of shaking than other geologic units.
![download usgs map for a region download usgs map for a region](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/info_block/public/thumbnails/image/TNMAdvancedViewerScreenshot02.jpg)
These new maps show a lower likelihood of liquefaction than previously thought in regions underlain by Bay mud that fringes many parts of San Francisco Bay. Other potentially hazardous areas include those along some of the larger streams, which produce the loose young soils that are particularly susceptible to liquefaction. Such areas along the Bay margins are found in San Francisco, Oakland and Alameda Island, as well as other places around San Francisco Bay. The highest hazard areas shown by the liquefaction hazard maps are concentrated in regions of man-made landfill, especially fill that was placed many decades ago in areas that were once submerged bay floor. We can expect history to repeat itself in the next big Bay Area earthquake.
![download usgs map for a region download usgs map for a region](https://www.researchgate.net/profile/Mark-Roth-3/publication/331936221/figure/fig1/AS:739283409330176@1553270308184/Regions-of-the-USGS-Amphibian-Research-and-Monitoring-Initiative-in-the-conterminous.jpg)
In addition, the California Geological Survey has zoned the greater San Francisco area for liquefaction hazard in their seismic hazard maps. The older map also shows locations of liquefaction observed in historical earthquakes, particularly the Great 1906 earthquake and the 1989 Loma Prieta quake. Please use the older map for areas not covered by the new map. Northern San Francisco and the Marin peninsula are not included in the new maps because geologic field mapping in these regions is incomplete. A previous USGS map, published in 2000, covers a larger region (outlined in black). These new maps cover the San Francisco Bay region (outlined in red). The Marina district, a shallow bay filled in after the 1906 earthquake, suffered some of the worst damage in the 1989 earthquake (USGS photo). Many regions of man-made landfill liquefied in the 1989 Loma Prieta earthquake. Photo on left shows Dore Street (Bancroft Library) and Howard & 17th Streets (G.K. Photos above show two low lying areas in San Francisco where damage from the 1906 earthquake was associated with liquefaction and ground failure. Regions of man-made landfill fared poorly in the 1906 San Francisco earthquake throughout the Bay Area. Liquefaction during large earthquakes commonly disrupts pipelines and road networks and also may cause buildings to settle and move downslope or toward stream banks. When the ground liquefies, it may lose its ability to support buildings and other structures. The second of the maps shows the likelihood that these young deposits will liquefy, or turn into a sandy liquid due to the strong shaking a big earthquake will produce.
![download usgs map for a region download usgs map for a region](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/video/youtube-QtRM9dGF2To.jpg)
Detailed mapping is needed to forecast where shaking will be strongest during future earthquakes. Soft muds on which it was constructed shook much more strongly than surrounding regions on stronger ground. Figure on the right (USGS photo) shows part of the Cypress structure, the freeway approach to the Bay Bridge from Oakland, which collapsed during the Loma Prieta earthquake, killing 42 people. Soft muds shake much harder than bedrock. Figure on left shows that the shaking experienced in a region depends very strongly on the type of deposits found near the surface.