Geology, ecosystems, land systems, and the forces shaping our planet.
A coastal lidar survey maps land and water by timing laser pulses from an aircraft. Millions of measurements become a three-dimensional record of beaches, dunes and submerged terrain. The method gives scientists a consistent view across the shoreline, where ordinary land surveys and boat-based sonar each become difficult. NOAA explains that lidar measures distance with…
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Glacial isostatic adjustment is the slow movement of Earth after the growth and melting of enormous ice sheets. Land beneath former ice is still rising in parts of Canada and Scandinavia, while some areas beyond the old ice margin are sinking as a broad bulge in the crust relaxes. NOAA’s explanation of glacial isostatic adjustment…
The words hurricane and typhoon both describe the same kind of rotating ocean storm within the broader tropical cyclone family. The preferred name changes with the ocean basin. A mature storm in the Atlantic is called a hurricane, while its counterpart in the western North Pacific is called a typhoon. NOAA’s comparison places hurricanes and…
The cryosphere is all the frozen water on Earth. It includes vast ice sheets and mountain glaciers, but also seasonal snow, frozen lakes, sea ice and ground that remains frozen for years. Some parts last only through winter, while Antarctic ice can preserve snow deposited hundreds of thousands of years ago. NOAA’s definition of the…
