0. The latest population estimate for Columbus from the U.S. Census Bureau is over 820,000.
These two images show Columbus and surrounding areas in 1986 and again in 2014. The second image shows the gray urban areas expanding into previous agricultural land, which is indicated by green patchy areas. The bright areas throughout the city are retail and industrial centers. The dark blue spots along the river in the southern part of the city are wastewater treatment ponds and other ponds associated with local sand and gravel quarries.
The historical record provided by Landsat images can be a useful tool for city managers, planners, and scientists who are monitoring and documenting the changes to Earth’s land cover caused by urban expansion.
A volcanic eruption that started on August 31 in Iceland shows no sign of weakening. This eruption is occurring at the Bardarbunga volcano, which lies north of the Vatnajökull glacier in south-central Iceland. Lava has been flowing spectacularly from the Holuhraun lava field, and the eruptive fissure has now spread lava across more than 70 square kilometers (27 square miles).
These Landsat 8 images show different spectral bands and band combinations acquired on September 6, 2014. These images provide examples of the type of information being used by scientists to monitor and map the eruption.
The first image is a false-color composite that combines information from the shortwave infrared, near-infrared, and green wavelengths of light. In this image, the recently erupted lava glows bright orange and red. The areas covered by snow and ice within the neighboring glacier can also be seen in shades of blue-green. The second image is a natural color representation, based on the visible wavelengths of light. In this image, the location of active volcanic fissures can be seen as small bright features, and the plumes and trajectory of ash and steam can also be clearly seen. The surface of the cooling lava flows (where visible) are black. The third image is a thermal infrared representation. 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 middl