Nature works in patterns, and one of those patterns is imprinted on the frozen Alaskan landscape in this true-color image from January 11, 2010. Like a winter-bare tree, a network of roots, or the veins, arteries, and capillaries that enclose an organ, the Yukon River branches across the snowy Yukon Delta to the Bering Sea.

The main branches of the river are bright white, the surface frozen and probably covered in snow. The smaller distributaries (the branches that break away from the main branch of the river) are darker, highlighted against the field of white that covers the rest of the delta region. Each branch flows into the Bering Sea, but the coastline is invisible in this image. The shallower water near shore has frozen, and the white sea ice blends with the white, snow-covered coast. The continuous field of white heightens the delta’s resemblance to a tree viewed against a cloudy sky.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this image on January 11, 2010. The highest resolution version of the image is provided above, but the image is also available in additional resolutions from the MODIS Rapid Response Team.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC.

At 4:53 p.m. local time on January 12, 2010, a 7.0-magnitude earthquake struck Hispaniola Island, just 15 kilometers (10 miles) southwest of the Haitian capital of Port-au-Prince. Besides its strong magnitude, the earthquake’s shallow depth of roughly 8.3 kilometers (5.2 miles) ensured that the densely populated capital suffered violent shaking.

This map shows the topography and tectonic influences in the region of the earthquake. Lighter colors indicate higher elevation. Black circles mark earthquake locations determined by the U.S. Geological Survey, and circle sizes correspond with quake magnitudes. Dozens of aftershocks followed the main quake. Red lines indicate fault lines.

The epicenter of the quake appears just south of the Enriquillo-Plaintain Garden Fault, the southernmost of two major east-west-trending faults that bear the stress of the convergence of the Caribbean and North America tectonic plates in this location. Though faults are weak spots or fractures in the Earth’s crust below the surface, very often there are topographical clues to their presence. In this case, the presence of the fault is indicated by long, straight valley cutting through southern Haiti, just south of Port-Au-Prince. The Enriquillo-Plaintain Garden Fault is a strike-slip type fault, with the Caribbean plate moving eastward with respect to the North America plate.

Image Credit: NASA Earth Observatory image by Jesse Allen, using earthquake and plate tectonics data from the USGS Earthquake Hazard Program, elevation data from the Shuttle Radar Topography Mission (SRTM) courtesy of the University of Maryland’s Global Land Cover Facility. Caption by Michon Scott and Rebecca Lindsey.

Maupiti Island

Spanning less than 10 kilometers (6 miles), Maupiti Island sits in the South Pacific Ocean, about 46 kilometers (29 miles) west of Bora Bora. The remote island lies 5,800 kilometers (3,600 miles) from Australia, and about 3,800 kilometers (2,400 miles) from New Zealand. Maupiti consists of a central island poking 213 meters (700 feet) above the sea surface, framed by low-profile serpentine islands and coral reefs that enclose a lagoon.

The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite captured this true-color image of Maupiti Island on August 8, 2009. The water inside the lagoon glows electric blue, surrounded by much paler blues of fringing coral reefs. Waves breaking on Maupiti’s southwestern shores appear brilliant white. Above the water line, forests carpet the islands. Only on the central island does the land rise high enough to cast a discernible shadow, and because this island sits in the Southern Hemisphere, the shadow falls to the south at this time of year. On the northeastern fringing island, the landing strip of a tiny airport cuts a long east-west line across vegetated land and coral reef.

AIRS Produces CO2 Snapshot

Above image was created with data acquired by the Atmospheric Infrared Sounder instrument (AIRS) on NASA’s Aqua satellite during July 2009. The image shows large-scale patterns of carbon dioxide concentrations that are transported around Earth by the general circulation of the atmosphere. Dark blue corresponds to a concentration of 382 parts per million and dark red corresponds to a concentration of almost 390 parts per million.

The northern hemisphere mid-latitude jet stream effectively sets the northern limit of enhanced carbon dioxide. A belt of enhanced carbon dioxide girdles the globe in the southern hemisphere, following the zonal flow of the southern hemisphere mid-latitude jet stream. This belt of carbon dioxide is fed by biogenesis activity in South America (carbon dioxide is released into the atmosphere through the respiration and decomposition of vegetation), forest fires in both South America and Central Africa, and clusters of gasification plants in South Africa and power generation plants in south eastern Australia.

The AIRS instrument flies on NASA’s Aqua satellite and is managed by the Jet Propulsion Laboratory, Pasadena, California, under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.