Earth’s Surface and Interior
In January 2013, intense bushfires blazed in Tasmania, an island south of Australia. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image showing numbers fires burning across the island on January 7, 2013. Red outlines indicate hot spots where MODIS detected unusually warm surface temperatures associated with fires. Read more.
ASTER Helps Map Ancient Settlements in Mesopotamia
A comparison of ASTER classification (left) and surface artifact distribution (right). In the image on the left yellow indicates a greater than fifty percent probability of finding artifacts and bright orange indicates that the probability is greater than eighty percent. In the image on the right blue indicates that there are less than two artifacts per square meter and red indicates that there are more than ten. Image courtesy of Bjoern Menze and Jason Ur
Remote sensing technology can be applied to archaeological survey methods helping archaeologists find sites and map the locations of past civilizations. However, the location alone is not enough to create an extensive and intensive record revealing the cycles of rising and falling settlements over many millennia. Two Harvard archealogists used remotely sensed data from ASTER and CORONA, to create a map that not only reflects the location of ancient civilizations, but also provides insight into the number of people living at each site and how often different sites were inhabited. Through identifying the volume of anthropogenic soils, or soils modified by humans, scientists were able to make a more complete record of the changing landscape of Mesopotamia over time. The CORONA program produced photographs that made it possible for the scientists to locate mounds of earth thought to be made by human settlement, but other satellite and aerial photography images needed to be used to create a more complete map. These images were then combined with multispectral images from satellite instruments including ASTER, which made it possible to determine whether or not the mounds contained anthropogenic soils. Using this technique, the scientists were able to create one of the largest systematic remote sensing records for an ancient landscape, including over fourteen thousand sites and covering approximately 22,000km2.
Menze, Bjoern and Ur, Jason. (2012, March 19). Mapping patterns of long-term settlement in Northern Mesopotamia at a large scale. Proceedings of the National Academy of Sciences.
An analysis of data from Terra’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument mapped the thermal characteristics of Hawaii’s Kilauea, Mauna Loa, Mauna Kea, Hualãlai, and Haleakalã volcanoes between 2000 and 2010. Images for all five areas were compiled and stacked to provide time series and temperature trends. Thermal areas were conspicuous on Kilauea, shown here, and Mauna Loa. The image on the right was produced by “œstacking” 42 individual surface kinetic temperature measurements of the Kilauea crater. The only significant change in thermal activity noted in the study period is the opening of the Halema”˜uma”˜u ventat Kïlauea’s summit in 2008. Researchers observed several small thermal anomalies that coincidewith pit craters on Hualälai. The anomalies most like result from the sheltered nature of the depression, but closer inspection is warranted to determine if genuine thermal activity exists in the craters. Thermal areas were not detected on Haleakalä or Mauna Kea.
Patrick, M.R., and Witzke, C.-N., 2011, Thermal mapping of Hawaiian volcanoes with ASTER satellite data: U.S. Geological Survey Scientific Investigations Report 2011-5110, 22 p., available at http://pubs.usgs.gov/sir/2011/5110/.