. This image shows relative surface temperature over the region, with the hottest areas (erupted lava) shown in bright hues and colder areas (glacial ice and water bodies) shown in dark tones.
The combined information available in Landsat images can provide an important complement to ground sensors. These images are important for scientists and decision makers engaged in mapping and monitoring the eruption.
As 2014 comes to an end, so does the growing season in the northern U.S. heartland. Millions of acres of corn, soybeans, alfalfa, and small grains have been harvested from the land in recent weeks.
These two Landsat images show the harvest activity and seasonal vegetation changes along the Platte River in south-central Nebraska. The river flows from the northwest corner of the images and then to the east, and its associated basin provides an important corridor for agriculture. The first image was acquired in early September. This image shows many actively growing fields (green blocks) across the landscape, especially within the Platte River basin. The second image (late October) is dominated by shades of tan, pink, and gray. These colors indicate bare ground, and only a small number of green fields remain.
Landsat data are often used for agriculture monitoring and management. This imagery can help users monitor local and regional conditions of the world’s croplands—within a growing season, from year to year, and from one decade to another.
Over 20 Million Landsat Scenes Downloaded October 29, 2014
Since 2008, all Landsat data—archived and newly acquired—have been available for free download. On September 16, 2014, users worldwide downloaded over 14,000 scenes from the servers at the USGS Earth Resources Observation and Science (EROS) Center. These downloads brought the total number of Landsat data downloads to more than 20 million.
This Landsat 8 scene was one of the many downloaded on September 16. It shows the area around Juneau, Alaska. Water is dark and includes Lynn Canal, the long water body in the middle 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 c