This statistic shows the total land and water area of the United States by state and territory. Alabama covers an area of 52,420 square miles.

This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Tree Ring. The data include parameters of tree ring with a geographic location of Alaska, United States Of America. The time period coverage is from 102 to -54 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data.

In 2023, Washington, D.C. had the highest population density in the United States, with 11,130.69 people per square mile. As a whole, there were about 94.83 residents per square mile in the U.S., and Alaska was the state with the lowest population density, with 1.29 residents per square mile. The problem of population density Simply put, population density is the population of a country divided by the area of the country. While this can be an interesting measure of how many people live in a country and how large the country is, it does not account for the degree of urbanization, or the share of people who live in urban centers. For example, Russia is the largest country in the world and has a comparatively low population, so its population density is very low. However, much of the country is uninhabited, so cities in Russia are much more densely populated than the rest of the country. Urbanization in the United States While the United States is not very densely populated compared to other countries, its population density has increased significantly over the past few decades. The degree of urbanization has also increased, and well over half of the population lives in urban centers.

The Wind Integration National Dataset (WIND) Toolkit, developed by the National Renewable Energy Laboratory (NREL), provides modeled wind speeds at multiple elevations. Instantaneous wind measurements were analyzed from more than 126,000 sites in the continental United States for the years 2007–2013. The model results were mapped on a 2-km grid. A subset of the contiguous United States data for 2012 is shown here. Offshore data is shown to 50 nautical miles.Time Extent: Annual 2012Units: m/sCell Size: 2 kmSource Type: StretchedPixel Type: 32 Bit FloatData Projection: GCS WGS84Mosaic Projection:  WGS 1984 Web MercatorExtent: Contiguous United StatesSource: NREL Wind Integration National Dataset v1.1

WIND is an update and expansion of the Eastern Wind Integration Data Set and Western Wind Integration Data Set. It supports the next generation of wind integration studies.

Accessing Elevation InformationEach of the 9 elevation slices can be accessed, visualized, and analyzed. In ArcGIS Pro, go to the Multidimensional Ribbon and use the Elevation pull-down menu. In ArcGIS Online, it is best to use Web Map Viewer Classic where the elevation slider will automatically appear on the righthand side. The elevation slider will be available in the new Map Viewer in an upcoming release.

What can you do with this layer?

This layer may be added to maps to visualize and quickly interrogate each pixel value. The pop-up provides the pixel’s wind speed value.

This analytical imagery tile layer can be used in analysis. For example, the layer may be added to ArcGIS Pro and proposed wind turbine locations can be used to Sample the layer at multiple elevation to determine the optimal hub height. Source data can be accessed on Amazon Web ServicesUsers of the WIND Toolkit should use the following citations:Draxl, C., B.M. Hodge, A. Clifton, and J. McCaa. 2015. Overview and Meteorological Validation of the Wind Integration National Dataset Toolkit (Technical Report, NREL/TP-5000-61740). Golden, CO: National Renewable Energy Laboratory.Draxl, C., B.M. Hodge, A. Clifton, and J. McCaa. 2015. "The Wind Integration National Dataset (WIND) Toolkit." Applied Energy 151: 355366.King, J., A. Clifton, and B.M. Hodge. 2014. Validation of Power Output for the WIND Toolkit (Technical Report, NREL/TP-5D00-61714). Golden, CO: National Renewable Energy Laboratory.

This data set provides a 38-year, 1-km resolution inventory of annual on-road CO2 emissions for the conterminous United States based on roadway-level vehicle traffic data and state-specific emissions factors for multiple vehicle types on urban and rural roads as compiled in the Database of Road Transportation Emissions (DARTE). CO2 emissions from the on-road transportation sector are provided annually for 1980-2017 as a continuous surface at a spatial resolution of 1 km.

This raster data set represents the saturated thickness of the High Plains aquifer of the United States, 2009, in feet. The High Plains aquifer underlies approximately 112.6 million acres (176,000 square miles) in parts of eight States: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. The aquifer's saturated thickness ranges from near zero to about 1,200 feet (Weeks and Gutentag, 1981). Water-level declines occurred in parts of the High Plains aquifer soon after the onset of substantial irrigation with groundwater (about 1950) (Luckey and others, 1981). This data set was generated in ESRI ArcInfo Workstation Version 9.3, which is a geographic information system (GIS), using an aquifer base raster data set, saturated-thickness data from wells measured in 2009 and from some additional wells in New Mexico, which were measured in 2005 through 2008, and a published map of the aquifer's saturated thickness in 1980 (Weeks and Gutentag, 1981). For this data set, (1) areas that Gutentag and others (1984) delineated as areas of "little or no saturated thickness" and (2) areas, generally near the aquifer boundary, with interpolated saturated thickness less than zero were set to a saturated thickness of 10 feet. REFERENCES CITED -- Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p. Luckey, R.R., Gutentag, E.D., and Weeks, J.B., 1981, Water-level and saturated-thickness changes, predevelopment to 1980, in the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-652, 2 sheets, scale 1:2,500,000. Weeks, J.B., and Gutentag, E.D., 1981, Bedrock geology, altitude of base, and 1980 saturated thickness of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Hydrologic Investigations Atlas HA-648, 2 sheets, scale 1:2,500,000.

This statistics shows a list of the top 20 largest-metropolitan areas in the United States in 2010, by land area. Riverside-San Bernardino-Ontario in California was ranked first enclosing an area of 70,612 square kilometers.

This digital data set consists of boundaries for areas of little or no saturated thickness within the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 106 degrees west longitude. The outcrop area covers 174,000 square miles and is present in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created by digitizing the areas of little or no saturated thickness from a 1:1,000,000-scale base map created by the U.S. Geological Survey High Plains Regional Aquifer-Systems Analysis (RASA) project (Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p.) The data are not intended for use at ...

Data depicts mean wave power density within U.S. waters. Estimates represent naturally available U.S. wave energy, derived from measurements observed during a 51-month study period. Measurements were taken from 42,000 grid points out to a distance of 50 nautical miles from shore. Values represent the average instantaneous power generated by a meter length of wave crest per grid point. In accordance with accepted global practice, wave power density is measured in kilowatts per meter (kW/m) of wave crest aggregated across a unit diameter circle. These data were classified using quantiles.

© DOE National Renewable Energy Laboratory This layer is a component of Ocean Wave Resource Potential.

Mean wave power density estimates represent naturally available US wave energy, derived from measurements observed during a 51-month study period. Measurements were taken from 42,000 grid points out to a distance of 50 nautical miles from shore. Values represent the average instantaneous power generated by a meter length of wave crest per grid point. In accordance with accepted global practice, wave power density is measured in kilowatts per meter of wave crest aggregated across a unit diameter circle. Data were classified using quantiles. Bathymetric effects are known to have a large effect on wave characteristics at depths shallower than ~20m on the east coast and ~50m on the west coast. Reliable site-specific information in shallow waters can only be produced using results from models with higher spatial resolution that include shallow-water physics. Results may not be accurate in the shallower waters of the inner continental shelf. These areas are indicated by dark gray regions. For more information pertaining to these areas please refer back to the source.

© MarineCadastre.gov

The United States has an average elevation of roughly 2,500 feet (763m) above sea level, however there is a stark contrast in elevations across the country. Highest states Colorado is the highest state in the United States, with an average elevation of 6,800 feet (2,074m) above sea level. The 10 states with the highest average elevation are all in the western region of the country, as this is, by far, the most mountainous region in the country. The largest mountain ranges in the contiguous western states are the Rocky Mountains, Sierra Nevada, and Cascade Range, while the Appalachian Mountains is the longest range in the east - however, the highest point in the U.S. is Denali (Mount McKinley), found in Alaska. Lowest states At just 60 feet above sea level, Delaware is the state with the lowest elevation. Delaware is the second smallest state, behind Rhode Island, and is located on the east coast. Larger states with relatively low elevations are found in the southern region of the country - both Florida and Louisiana have an average elevation of just 100 feet (31m) above sea level, and large sections of these states are extremely vulnerable to flooding and rising sea levels, as well as intermittent tropical storms.

Product shows local sea surface temperatures (degrees C). It is a composite gridded-image derived from 8-km resolution SST Observations. It is generated every 48 hours for North America. SST is defined as the skin temperature of the ocean surface water.

The primary goal of the Circumpolar Active Layer Monitoring (CALM) program is to observe the response of the active layer and near-surface permafrost to climate change over long (multi-decadal) time scales. The CALM observational network, established in the 1990s, observes the long-term response of the active layer and near-surface permafrost to changes and variations in climate at more than 200 sites in both hemispheres. CALM currently has participants from 15 countries. Majority of sites measure active-layer thickness on grids ranging from 1 hecatre to 1 square kilometer, and observe soil temperatures. Most sites in the CALM network are located in Arctic and Subarctic lowlands. Southern Hemisphere component (CALM-South) is being organized and currently includes sites in Antarctic and South America. The broader impacts of this project are derived from the hypothesis that widespread, systematic changes in the thickness of the active layer could have profound effects on the flux of greenhouse gases, on the human infrastructure in cold regions, and on landscape processes. It is therefore critical that observational and analytical procedures continue over decadal periods to assess trends and detect cumulative, long-term changes. The CALM program began in 1991. It was initially affiliated with the International Tundra Experiment and has been supported independently and continuously since 1998 through grants from the United States National Science Foundation (NSF). CALM is funded by the NSF Award 1304555 (Polar Programs). This dataset and metadata record was automatically generated from a web crawl of the original project page https://www2.gwu.edu/~calm/data/north.htm at the request of project coordinators. More information about this site and others in the project can be found at https://www2.gwu.edu/~calm/data/north.htm and also http://gtnpdatabase.org/activelayers .

This digital data set consists of saturated thickness contours for the High Plains aquifer in the central United States. The High Plains aquifer extends from south of 32 degrees to almost 44 degrees north latitude and from 96 degrees 30 minutes to 106 degrees west longitude. The outcrop area covers 174,000 square miles and is present in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital data set was created by digitizing the saturated thickness contours from a 1:1,000,000-scale base map created by the U.S. Geological Survey High Plains Regional Aquifer-System Analysis (RASA) project (Gutentag, E.D., Heimes, F.J., Krothe, N.C., Luckey, R.R., and Weeks, J.B., 1984, Geohydrology of the High Plains aquifer in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming: U.S. Geological Survey Professional Paper 1400-B, 63 p.) The data are not intended for use at scales larger than 1:1,000,000.

This data displays the LRS mileages to a .01 accuracy. It represents a real world driven measure from the lateral extension of the curb at the beginning and end of a particular roadway. This three dimensional measure is then set in the two dimensional Linear Referencing Services (LRS) space and the lengths are distributed along particular segments which in some cases may cause a stretching or shrinking effect to the real world measures. Also not all reverse measurements, particularly in an overlap section, are able to be represented due to the nature and digitizing rules when creating the LRS.

description: The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted multibeam bathymetric data within specific areas of special interest. The composite bathymetric grid in Geographic presented herein covers a roughly 156 km square area (surveys H11252 and H11361) of the sea floor in the area near Six Mile Reef, eastern Long Island Sound. The original multibeam bathymetric data were collected during 2004 as part of charting applications aboard the NOAA Survey Vessel Thomas Jefferson. A Simrad EM1002 multibeam system mounted on the hull of this vessel was used to acquire data along survey lines from the deeper water (>20 m) parts of the survey areas. Two 29-foot launches with hull-mounted Reson systems were deployed from the ship and were used to acquire data along survey lines from the shallower areas. Detailed bathymetric data and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The bathymetric data models also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.; abstract: The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted multibeam bathymetric data within specific areas of special interest. The composite bathymetric grid in Geographic presented herein covers a roughly 156 km square area (surveys H11252 and H11361) of the sea floor in the area near Six Mile Reef, eastern Long Island Sound. The original multibeam bathymetric data were collected during 2004 as part of charting applications aboard the NOAA Survey Vessel Thomas Jefferson. A Simrad EM1002 multibeam system mounted on the hull of this vessel was used to acquire data along survey lines from the deeper water (>20 m) parts of the survey areas. Two 29-foot launches with hull-mounted Reson systems were deployed from the ship and were used to acquire data along survey lines from the shallower areas. Detailed bathymetric data and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The bathymetric data models also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.

These data represent the centerline and measured increments at hundredths, tenths and whole miles, along the centerline of the Colorado River beginning at Glen Canyon Dam near Page, Arizona and terminating near the inflow s of Lake Mead in the Grand Canyon region of Arizona, USA. The centerline was digitized using Color Infra-Red (CIR) orthophotography collected in March 2000 as source information and a LiDAR-derived river shoreline representing 8,000 cubic feet per second (CFS)as the defined extent of the river. Every effort was made to follow the main flow of the river while keeping the line approximately equidistant from both shorelines. The centerline feature class has been created to more accurately map locations along the Colorado River downstream of the Glen Canyon Dam. River miles and river kilometers were developed from measurements along this line. The incremental point feature classes were derived from the centerline of the Colorado River datasets. Specifically, the points were generated from nodes extracted from the centerline endpoints of the tenth mile line feature class. The Grand Canyon Monitoring and Research Center (GCMRC) river mileage was cross-checked with commercially available river guides and always fell within one mile of the guides, usually corresponding within a half mile. Additionally, these data were subjected to internal review by GCMRC scientists and commercial boatmen with decades of river travel experience on the Colorado River. River Mile 0 was measured from the USGS concrete gage and cableway at Lees Ferry, Arizona -- as per the Colorado River Compact of 1922 -- with negative river mile numbers used in Glen Canyon and positive river mile numbers downstream in Marble and Grand Canyons. These data were updated in March 2015 using newer ortho-rectified imagery collected in May of 2009 and 2013, both at approximately 8,000 CFS. Due to extended drought conditions that have persisted in the U.S. Southwest, lake levels have dropped dramatically, especially at Lake Mead. A stretch of the Colorado River corridor that was part of Lake Mead in year 2000 has returned to a flowing river once again, and with a different channel that has not previously existed. All changes to the original centerline are downstream of River Mile 260 which is just upstream of Quartermaster Canyon in western Grand Canyon. New river miles and river kilometers were developed from this updated centerline.

Paleomagnetic, rock magnetic, or geomagnetic data found in the MagIC data repository from a paper titled: Creer, K.M. (1958). Preliminary palaeomagnetic measurements from South America. Annales de Geophysique 14: 373-390.

Measurements of changes in the distance (or length) between monuments are provided. These measurements were made using a two-color Electronic Distance Meter (EDM) that can measure distances between 1 and 10 KM. Nominal precision of these data range from 0.3 mm to 1.0 mm dependent upon the baseline’s length. These measurements were made between mid-1975 to mid-2006. Data in this archive are from eight networks, each consisting of more the 9 baselines. The locations of these networks in California include far northwestern California, Hollister, CA., Long Valley Caldera in eastern California, Parkfield, Pearblossom, and Anza; the last two located in Southern California. For four of the networks (Hollister, Parkfield, Long Valley, and Pearblossom), measurements were made roughly once per day with the goal of documenting transient deformation associated with earthquake and/or volcanic areas. Measurements of the other networks were less frequent from a few times each year to annual meas ...

Various shipping zones delineate activities and regulations for marine vessel traffic. Traffic lanes define specific traffic flow, while traffic separation zones assist opposing streams of marine traffic. Precautionary areas represent areas where ships must navigate with caution, and shipping safety fairways designate where artificial structures are prohibited. Recommended Routes are predetermined routes for shipping adopted for reasons of safety. Along certain zones of the East Coast of the United States, ships are also required to report vessel location within designated endangered species areas, such as the North Atlantic right whale. Particularly Sensitive Sea Areas need special protection because of their vulnerability to damage by international maritime activities. Areas to be Avoided are within defined limits where navigation is particularly hazardous or it is exceptionally important to avoid casualties and should be avoided by all ships or certain classes of ships.Area to be Avoided: These areas are limited with respect to the kinds of vessels or actions required to be taken by those vessels. These restricted areas include national marine sanctuaries, particularly sensitive seas, and critical habitats. An area to be avoided or ATBA is a ships’ routing measure that comprises an area within defined limits in which either navigation is particularly hazardous or it is exceptionally important to avoid casualties and should be avoided by all ships or certain classes of ships.Mandatory Ship Reporting for Protection of Right Whales: A mandatory ship reporting may be adopted by International Maritime Organization (IMO) to contribute to the safety of life at sea, the safety and efficiency of navigation and/or the protection of the marine environment. In such areas, ships are required to report in to a shore-based authority and such authority shall have the capability of interaction with participating ships.Particularly Sensitive Sea Area: Designation of a Particularly Sensitive Sea Area (PSSA) is a comprehensive management tool at the international level for reviewing attributes within an area that are vulnerable to damage by international shipping and for determining the most appropriate protective measures available.Precautionary Area: A routing measure comprising an area within defined limits where vessels must navigate with particular caution and within which the direction of traffic flow may be recommended.Recommended Shipping Routes: NOAA established the recommended vessel routes to reduce the likelihood of ship collisions in key right whale habitats. It means a route of undefined width, for the convenience of vessels in transit, which is often marked by center-line buoys.Separation Zone: A mile-wide zone or line separating the traffic lanes in which vessels are proceeding in opposite or nearly opposite directions; or from the adjacent sea area; or separating traffic lanes designated for particular classes of vessels proceeding in the same direction.Shipping Safety Fairways: Shipping fairways data means a lane or corridor in which no artificial island or structure, whether temporary or permanent, will be permitted so that vessels using US ports will have unobstructed approaches. Inshore Traffic Lane or Zone: A routing measure comprising a designated area between the landward boundary of a traffic separation scheme and the adjacent coast.Dataset SummaryThe data for this layer were obtained from NOAA's Coastal Services Center ftp website (ftp://ftp.csc.noaa.gov/pub/MSP/) and is updated regularly. The polygon features in this layer contain attributes for the type of lane or zone. Link to source metadataWhat can you do with this layer?This layer is a feature service, which means it can be used for visualization and analysis throughout the ArcGIS Platform. This layer is not editable.

The High Plains aquifer extends from about 32 degrees to almost 44 degrees north latitude and from about 96 degrees 30 minutes to 106 degrees west longitude. The aquifer underlies about 175,000 square miles in parts of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. This digital dataset consists of three sets of water-level measurements. The first set are the supplemental water-level measurements for 547 wells screened in the High Plains aquifer, not located in New Mexico, measured in predevelopment and at least once for 2015 through 2018, but not for 2019. These supplemental measurements were used to calculate historical water-level change values for predevelopment to 2015 to 2018 and approximate water-level change values from predevelopment to 2019 to substantiate the map of water-level changes, predevelopment (about 1950) to 2019 (figure 1 in https://doi.org/10.3133/sir20235143). The water-level measurements used to calculate historical wate ...