e of the image. Green is vegetation and forested mountain areas.
This image also provides a clear view of the Juneau Icefield. Several glaciers flow from this icefield, and glaciologists are using the 42-year Landsat archive to monitor the advance and retreat of the glaciers over time. Since Landsat 7 and Landsat 8 together provide an 8-day repeat cycle, Landsat can be an important supplement to ground-based glacier monitoring.
Scientists, students, city planners, environmental engineers, and many others have been able to use the vast archive of Landsat data free of charge to support and enhance their research. The free availability of Landsat data enables scientists to conduct large-scale global studies that would otherwise be too costly.
Urban Growth of Maracaibo, Venezuela October 22, 2014
The city of Maracaibo, Venezuela, is located on the western shore of a strait that connects Lake Maracaibo to the Gulf of Venezuela. The region is an important source of oil production for Venezuela, and Maracaibo serves as a major port for shipments of oil. This area is also known for its commercial fisheries, shrimp farming, and salt production.
These two Landsat images show the urban expansion of the city of Maracaibo between 1986 and 2014. Cities along the lake to the east and south have also grown.
The 40-year archive of Landsat data is useful for studying many types of change across the Earth’s surface, including changes due to urban growth, agricultural activities, and coastal land use.
The Huang He (Yellow) River in China is the most sediment-filled river on Earth. It flows from the Bayan Har Mountains to the Bohai Sea. Along the way, it crosses a soft plateau that is covered with fine, wind-blown soil. The river carries away millions of tons of this delta-building material every year. Over time, the river carries its sediment load farther outward into the sea. These Landsat images provide a view of the dramatic changes to the shoreline.
Besides changes to the delta, aquaculture has significantly expanded along the coastline near the river delta, as well as farther south along Laizhou Bay. The dark geometric shapes along the coast were built on what were once tidal flats. These ponds hold shrimp and other types of seafood.
Landsat imagery is useful in providing historical records of the changes taking place on the Earth’s surface, and future acquisitions will allow scientists to help in protecting the delta’s natural wetlands, while meeting the demands of development along the shoreline.
As a 3-year drought continues in the western United States, water levels have been dropping in many California reservoirs, leading to emergency water use restrictions across the state.
These two Landsat images show the changing shoreline of Shasta Lake reservoir in northern California over the past three years. The first image was collected in September 2011 and shows the shoreline when the reservoir’s water levels were at 77 percent of total capacity. The tan colors in the September 2014 image show the change in shoreline. Even though snowmelt slightly increased the lake level earlier in 2014, the reservoir was still at only 27 percent capacity when this more recent image was acquired.
The lower right portion of the second image also shows a recent burn scar from the Gulch Fire. This fire was officially contained one day before the September 17 image was collected.
The images collected by Landsat are an important tool for monitoring changes to the earth’s surface, and can help support analysis related to water resources and other environmental conditions for affected communities.
Mapping Biodiverse Highlands with Satellite Imagery and Advanced Elevation Data September 23, 2014
A team from the USGS Earth Resources Observation and Science (EROS) Center produced a detailed land use/land cover map using Landsat satellite and 30-meter elevation data from the Shuttle Radar Topography Mission (SRTM) of the highlands along the Senegal-Guinea border. The Dindefelo Nature Reserve was created to protect the high biodiversity of this area, including ch