From the Guardian:
"This Envisat image shows the Ganges delta in the south Asia area of Bangladesh and India. The delta plain, about 350km wide along the Bay of Bengal, is formed by the confluence of the rivers Ganges, the Brahmaputra and Meghna. The colour effect comes from variations in the Earth's surface that occurred when three Envisat radar acquisitions taken over the same area at different times were combined"
"In the chilly waters of the Barents Sea, off the north-western corner of Russia, the ocean switched on its carbon dioxide vacuum during August: a giant bloom of single-celled, plant-like organisms called phytoplankton. During these blooms, which can cover thousands of square kilometres of the surface of the ocean, a litre of seawater may contain a billion or more phytoplankton cells, each one a microscopic chemical factory that vacuums carbon dioxide out of the surrounding seawater and uses photosynthesis to turn it into stored chemical energy. The milky-blue colour that dominates the bloom suggests that it contains large numbers of coccolithophores, phytoplankton that arm themselves with tiny calcium carbonate (chalk) scales. Chlorophyll and other light-harvesting pigments from other species of phytoplankton can add darker blues, greens, and reddish-browns to the bloom."
"Mount Hood is located within the Cascade range of the western United States, and it is the highest peak in Oregon at 3,426m. The Cascade Range is characterised by a line of volcanoes associated with a slab of oceanic crust that is descending underneath the westward-moving, continental crust of North America. Magma generated by this process rises upward through the crust and feeds a line of active volcanoes that extends from northern California in the United States to southern British Columbia in Canada. While hot springs and steam vents are still active on Mount Hood, the last eruption from the volcano occurred in 1866. The volcano is considered dormant, but still actively monitored."