Earth Observer

EarthObserver App©

Update! June 23, 2020:  EarthObserver is no longer being supported in IOS greater than 6

We are abandoning further development of the the app for the iPad and iPhone and will be transferring it to a WEB page.

EarthObserver is a mobile application created at the Lamont-Doherty Earth Observatory of Columbia University in the City of New York specifically for the iPhone®, iPod touch® and iPadTM. EarthObserver can be purchased from the Education Category of the Apple App StoreSM for $0.99.

With EarthObserver we invite you to visit and learn about our planet’s terrestrial landscapes, oceans and seas, frozen ice caps, atmosphere and clouds, geologic terrains, topography, nautical charts, natural hazards, human impacts, and many other earth and environmental science topics as you travel and explore with your finger .


  • Three map projections: Mercator, North Polar, South Polar
  • Global multi-resolution digital elevation model for land and ocean to a horizontal resolution of 10 meters for the US mainland, 30 meters elsewhere and 4 meters in some US coastal harbors and estuaries
  • New: Ability to show a place mark at your current location
  • Scrollable and cascading list of available topics
  • Overlay of selected thematic content on the base map with adjustable opacity
  • Info button for each subject that opens a browser window with content description, data sources, credits and citations along with external links
  • Legend text and numerical values revealed at locations tapped by your finger
  • Capture of current map to photo library for email to others
  • Automatic saving of last region viewed prior to exit from the app
  • Names of continents, oceans, seas, mountains, lakes, rivers, cities and seabed features automatically selected by zoom level
  • Overlays of coastlines, country, state and province boundaries
  • Instructions available upon startup


Wi-Fi or 3G network connection (iPhone, iPad) required with iOS 3.2 or more recent operating system. Recently retrieved tiles are cached to allow limited review of previously explored regions without a live connection.

Overview of Content

EarthObserver provides these main topics and sub-topics:

  • Basemap (computer-generated color-shaded relief of land and ocean floor)
  • US Coastal Bathymetry (with color palette appropriate to provide details of bays, sounds, estuaries, harbors and rivers)
  • US Nautical Charts (paper raster and digital electronic at all scales for Atlantic, Pacific, Gulf of Mexico, Bering Sea, Arctic and Great Lakes)
  • US Topographic Sheets (entire USGS collection for US mainland, Alaska, Hawaii and Puerto Rico)
  • Geologic Maps (entire world, by continent, by country and by US state showing formation ages, names and rock types)
  • Geophysical Maps (global earthquakes, tectonic plates and boundaries, gravity anomalies, geoid height, magnetic anomalies and the configuration of world stress)
  • Land Surface (temperatures day and night, primary productivity, vegetation index, land cover classifications and diversity, forest cover types and fragmentation)
  • NASA Visible Earth (global earth scenes for each month)
  • Ocean Floor (crustal age, sediment types, sediment thickness, seabed heatflow, seafloor true color, seafloor spreading rates, manganese nodules)
  • Ocean Surface (temperature, salinity, primary productivity, temperature during the prior ice age)
  • Human Impact (area per person, human footprint index, population density (2010), infant mortality rate, underweight children)
  • Hydrology (river drainage basin outlines, drainage networks, river flow accumulation)
  • Natural Hazards (cyclones, drought, earthquakes, floods, landslides, tornadoes, volcanic eruptions)
  • Atmosphere and Clouds (aerosols, carbon monoxide, cloud fraction, cloud optical thickness, cloud particle radius, cloud reflectance, cloud water content, radiation, solar insolation)
  • Snow, Ice and Water (ice cover, permafrost cover, snow cover, snow-water equivalent, water leaving radiance, water vapor)
  • Shorelines and Political Boundaries (countries, provinces, states, maritime)

Companion Applications

Free companion applications that run on Windows, Unix/Linux and Mac OS X can be used to display the EarthObserver content, and provide additional content and tools for interactive analysis and graphing:

  • GeoMapApp: an earth science exploration and visualization application that provides access to thousands of data sets, options for importing your own data, and analytical capabilities.
  • Virtual Ocean: integrates the GeoMapApp tool suite with 3-D earth browser technology to create a powerful new platform for interdisciplinary research and education.


The development of the Global Multi-Resolution Topography "Basemap" has been funded by the U.S. National Science Foundation as part of the Marine Geoscience Data System. This on-going synthesis is only possible through the efforts of thousands of scientists, technicians, officers and crew members aboard oceanographic research and survey ships and their counterparts in federal and state agencies that have been mapping and charting since the 1930's and with the digital elevation models generated by the NASA SRTM and ASTER Mission teams and their supporting institutions.

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