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.