Atlantic-facing coast of Chatham, MA, and its harbor. South of the mainland, North and South Monomoy Islands stand apart from each other and the coast.
Thirty-one years later, Landsat 8 reveals a landscape reshaped by the natural ebb and flow of waves, currents, winds, and tides. The changes are both subtle and substantial. Storms have breached the barrier spit in several places. By September 2015, the Monomoy islands have grown together. At the same time, waters around North Monomoy are shallower with sandbars and shoals closer to the water surface.
Time and the forces of nature will continue this reshaping of the barrier system. As they do, Landsat’s continuous monitoring will be there to document it.
Landsat Helps Battle Pine Beetle Hordes April 4, 2016
At the size of a grain of rice, the mountain pine beetle’s subtle assault on America’s forests isn’t always obvious to the naked eye. Yet over time, their armies of thousands can ravage entire mountainsides. That’s why the continuous monitoring abilities of Landsat satellites have become so important in fighting the insect hordes.
The U.S. Geological Survey’s (USGS) decision in 2008 to make what is now 44 years of archived satellite data free for distribution gave rise to time-series imagery that has become a powerful tool in revealing forest change. Landsat’s no-cost access gives forest managers an important and economical asset in discerning where outbreaks are happening as they occur. That knowledge in turn enables them to make more informed decisions on thinning tree stands affected by beetles, thus minimizing the potential fire threat they pose.
The value of continuous monitoring is readily apparent in these images. In August 1992, Landsat 5 focused on a swath of the Uinta Mountains just east of Salt Lake City, Utah. The shades of dark green indicate areas of healthier undisturbed forest. Almost exactly 18 years later, Landsat 5 found something much different—dark red stains readily visible throughout the image that tell a story of widespread pine beetle destruction.
Because they only measure field plots once a decade, Forest Service crews may have a harder time grasping the enormity of the assault. With Landsat’s continuous monitoring, the size and timing of infestations become much clearer.
Mississippi River Floods Deep South March 29, 2016
Late winter storms March 10–12, 2016, drenched areas of Louisiana, eastern Texas, Mississippi, and Arkansas with up to 20 inches of rain, causing significant damage and evacuations.
Louisiana officials say the resulting flooding there is among the most widespread for any non-hurricane event ever seen. These images acquired by Landsat 8 clearly capture the scope of that historical inundation.
Though earlier storms in January had already pushed the Lower Mississippi River toward the top of its banks, the meandering waterway appears largely contained in the image on the left, acquired March 4, 2016. Sixteen days later, however, the satellite’s sensors reveal something much more dramatic.
In the center of the March 20 image, the deep blue floodwaters spill on to the landscape surrounding Vicksburg, MS. At the bottom center, the river is engorged just south of Natchez, MS, as it flows off the image on its way to Baton Rouge, LA.
Smaller tributaries west across the border in Louisiana show the impact of the drenching rains as well, testifying to the most widespread flooding in the region since Hurricanes Isaac (August 2012) and Katrina (August 2005).
When the Earth shook Alaska 52 years ago—on Good Friday, March 27, 1964—tsunamis wiped out entire villages. Landslides swept Anchorage neighborhoods into Cook Inlet. A collision of tectonic plates comprising the planet’s outermost layer had caused a 9.2 magnitude earthquake, the largest in U.S. history, and killed 131 people.
Aerial photographs archived at the USGS Earth Resources Observation and Science (EROS) Center capture the quake’s dramatic impact on Anchorage’s coastal boundaries. In the 1953 image, the Turnagain neighborhood west of the city’s downtown area is only beginning to