is Landsat mosaic of four different scenes shows the geologic feature in false color. By blending visible and infrared wavelengths (bands), scientists can enhance the visibility of the various rock layers in contrast to the surrounding sand (yellow to white).
The largest mud volcano in the world is located in Porong, Sidoarjo in Indonesia, where it is locally called the Lusi Mud Volcano. Mud volcanoes are created when hot mud (rather than lava) erupts from a vent on the Earth’s surface. This type of eruption typically includes a mixture of steam and gas, groundwater, and mud-based slurry.
Lusi first erupted in May 2006, and is expected to continue erupting for decades. So far, enough mud has erupted to cover nearly 27,000 football fields in a meter of mud. These two Landsat images were acquired by Landsat 7 on April 28, 2006 (left) and June 24, 2015 (right). The round feature in the center of the right-hand image shows the current extent of the mudflow. This second image also shows a series of levee structures that were built in 2008 to surround and contain the ongoing mudflows.
The Landsat sensors include numerous spectral bands that can be used in various combinations, allowing users to accentuate and study specific features on the Earth’s surface. These two images used a combination of shortwave and near-infrared wavelengths to highlight the mudflow area, in contrast to the surrounding urban and agricultural areas.
The afternoon of Sunday June 14, Alaskan authorities were notified of a 40-acre fire in Willow, AK. Named the Sockeye Fire for the street where the fire began, the fire moved quickly through the black spruce forested area due to flat topography and hot, dry, windy weather. In only 48 hours, the burned area grew to about 6,500–7,000 acres. Strong north winds are expected to drive the fires to the south, threatening populated areas. Smoke could affect Anchorage, 80 miles to the south.
These two Landsat images were acquired by Landsat 8 on May 30, 2015 (left) and June 15, 2015 (right). Bright red indicates where the fire is burning. Burned areas are dark shades, and smoke from the fire forms a hazy trail toward the south. The Susitna River, to the west of the burned area, acts as a natural firebreak.
Landsat imagery assists with response planning and identification of areas at further burn risk. Future Landsat imagery will be useful for mapping and measuring burned areas and monitoring vegetation recovery.
Heavy rains fell over Texas, Oklahoma, Arkansas, and Louisiana in late May 2015. Many lakes and rivers filled and overflowed their banks, causing widespread flooding in both urban and rural areas. These rains provided much-needed moisture for this area of the southern Plains, and may help to suspend a multiyear drought in the region. However, the rapid rate of the rainfall has been excessive for many areas.
These images show the Trinity River southeast of Dallas, Texas. In the May image, the river can hardly be seen because of the vegetation along its banks. The June image shows Trinity River and flooded regions in bright blue and dark tones.
As the water moves downstream, continued flooding is affecting many homes, businesses, and cropland within Texas and its neighboring states. Future Landsat images will help with the monitoring and evaluation of impacts, as the waters crest and begin to recede.
2015 Earthquake and Landslides, Nepal May 27, 2015
A magnitude 7.8 earthquake struck Nepal on April 25, 2015. Along with damage due to shaking, the earthquake and its aftershocks triggered many large and small landslides throughout the region. As of early May, over 3,000 individual landslides had been identified, based on analysis of hundreds of satellite images collected after the earthquake.
The background image above is a Landsat 8 mosaic of the entire region, produced by stitching together Landsat images acquired from 2013–2014.
The insets show an image pair acquired by WorldView-2 and WorldView-3 over one example location near the town of Namrung, Nepal. Comparing the image acquired shortly after the earthqua