FYFD

Tag: satellite image

  • Sedimentation After Flooding

    Sedimentation After Flooding

    The new year brought California a series of atmospheric rivers that poured record amounts of water onto drought-stricken lands. While the precipitation refreshed snowpacks and reservoirs, much of it washed away as soils oversaturated. Those flows carried sediment with them, creating swirls of brown and green along the coastline.

    Compare the two satellite images above to see how different January 2022 looked from January 2023, post-deluge. The snow levels in January 2023 were about 248 percent of their average level for that part of the season. But the sediment levels in the ocean are also drastically increased, indicating high levels of erosion. (Image credit: J. Stevens; via NASA Earth Observatory)

  • Where Fresh and Salty Meet

    Where Fresh and Salty Meet

    Waterways twist through the wetlands of Adair Bay in this astronaut-captured image of northwestern Mexico. The estuary marks the transition between the Great Altar Desert and the Gulf of California. Fresh and salt water mix in the sediment-rich waterways. Mangroves and other salt-tolerant vegetation flourish in the coastal marsh. During low tides, evaporating water leaves behind salt flats, seen here in gray and white. High tides flood the area with nutrients that support both the vegetation and abundant aquatic life. (Image credit: NASA; via NASA Earth Observatory)

  • Vietnam’s Emerald Isles

    Vietnam’s Emerald Isles

    Vietnam’s Hạ Long Bay is home to more than 1,600 islands, many of them made up of mountainous limestone. The area is famous for its karst features, a type of terrain formed from highly porous, water-soluble rock. Over time, water dissolves and fractures the limestone, creating karst landscapes full of caves, springs, sinkholes, and fluted rock outcroppings. The area’s erosion also produces highly fertile soil, leading to a verdant ecosystem with many unique and endemic species. (Image credit: N. Kuring/NASA/USGS; via NASA Earth Observatory)

  • Summer Melt

    Summer Melt

    A warm summer in 2022 has resulted in record melting on Svalbard. Located halfway between the Norwegian mainland and the North Pole, more than half of Svalbard is normally covered in ice. But with glaciers in retreat and firn — a surface layer of compressed porous snow — melting, pale blue ice is getting direct exposure to the sun and warm air temperatures. The result has been melting 3.5 times larger than the average melt between 1981 and 2010. Look closely and you’ll find deep blue meltwater ponds dotting the ice, too. The run-off of meltwater has likely carried extra sediment into the surrounding waters, accounting for some of the paler water colors along the coast. (Image credit: J. Stevens/USGS; via NASA Earth Observatory)

  • Cloud Streets

    Cloud Streets

    Parallel lines of cumulus clouds stream over the Labrador Sea in this satellite image. These cloud streets are formed when cold, dry winds blow across comparatively warm waters. As the air warms and moistens over the open water, it rises until it hits a temperature inversion, which forces it to roll to the side, forming parallel cylinders of rotating air. On the rising side of the cylinder, clouds form while skies remain clear where the air is sinking. The result are these long, parallel cloud bands. (Image credit: J. Stevens; via NASA Earth Observatory)

  • Blooms in the Black Sea

    Blooms in the Black Sea

    The Black Sea gains its name from its dark waters, but those waters don’t stay dark year-round. In this natural color satellite image, streaks of milky blue bloom through the summer waters, thanks to the presence of a species of phytoplankton armored with white calcium carbonate. Despite their microscopic size, the phytoplankton’s presence is visible from space. During other parts of the year, like the spring, another species of phytoplankton dominates the Black Sea, turning its waters darker. (Image credit: J. Stevens; via NASA Earth Observatory)

  • Florida’s Keys

    Florida’s Keys

    Stretching from the southern tip of Florida, a chain of low-lying islands, known as keys or cays, formed underwater during a warm interglacial period some 125,000 years ago. Originally coral reefs and sand bars, the islands hardened and fossilized when sea levels dropped during an ice age. These natural-color satellite images hint at the keys’ impressive ecosystems. The bright blue streak is a giant coral reef separating the deeper waters of the Atlantic from the shallow waters and sea-grass beds lying between the islands. Formations like these, along with mangrove forests, are part of nature’s way to mitigate the damage and flooding caused by hurricanes. Unfortunately, warmer seas and rising sea levels now threaten the keys. (Image credit: L. Dauphin/USGS; via NASA Earth Observatory)

  • Actinoform Clouds

    Actinoform Clouds

    Flower-shaped actinoform clouds, like those seen on the left side of this satellite image, were only discovered in the 1960s once satellite imagery allowed meteorologists to identify cloud structures that were too large to recognize from the ground. Often appearing over the ocean, these clouds can stretch over hundreds of kilometers, bringing drizzling rain.

    This particular set of actinoform clouds have some distinctive neighbors in the right side of the image, where V-shaped slashes through the cloud cover mark the origins of two von Karman vortex streets. The vortex streets appear downwind of two rocky islands, Alejandro Selkirk Island and Robinson Crusoe Island. (Image credit: L. Dauphin; via NASA Earth Observatory)

  • Submarine Eruptions

    Submarine Eruptions

    The green-blue plume on the left of this satellite image is an eruption from Kavachi, an underwater volcano in the Solomon Islands. Kavachi’s crest is currently estimated to lie 20 meters below the surface, with its base at a depth of 1.2 kilometers. Eruptions are quite common at the volcano, but that doesn’t stop wildlife — like hammerhead sharks! — from making the crater their home. Over the last century, Kavachi’s eruptions have repeatedly formed small islands at the surface, but they were quickly eroded away by wave action. (Image credit: J. Stevens/NASA/USGS; via NASA Earth Observatory)

  • Surf’s Up

    Surf’s Up

    Surfers flock to northern Peru to enjoy what’s been called the world’s longest wave. These waves are generated by storms thousands of miles away in the Pacific and Southern Oceans. In the open water between, the waves sort themselves into groups of similar wavelength and speed. With the deep water off Peru, the large swells continue to travel together until close to the shore. Surfers also benefit from the tendency for incoming waves to arrive nearly parallel to the coastline, creating long shoreline stretches for breaking. Where many famous wave breaks can be ridden for seconds, surfers can ride these for minutes! (Image credit: L. Dauphin; via NASA Earth Observatory)