Old lava tubes are common on many volcanoes. There are lava tubes near the summit of the volcano on Santa Cruz Island. On the seafloor, lava tubes have been observed at mid-ocean ridges. They are believed to be responsible for helping to distribute lava to great distances away from eruption sites.
Geologists think lava tubes may also be present on the Moon and Mars. Scale across photo is about 1 meter. Lava Slideshow He uses techniques that span isotope geochemistry, next generation DNA sequencing, and satellite tagging to study the ecology of a wide variety of ocean species.
He recently discovered that blue sharks use warm water ocean tunnels, or eddies, to dive to the ocean twilight zone, where they forage in nutrient-rich waters hundreds of meters down.
Born in New Zealand, Simon received his B. With much of his work in the South Pacific and Caribbean, Simon has been on many cruises, logging 1, hours of scuba diving and hours in tropical environs. He has been a scientist at Woods Hole Oceanographic Institution since Gregory Skomal is an accomplished marine biologist, underwater explorer, photographer, and author. He has been a fisheries scientist with the Massachusetts Division of Marine Fisheries since and currently heads up the Massachusetts Shark Research Program.
For more than 30 years, Greg has been actively involved in the study of life history, ecology, and physiology of sharks. His shark research has spanned the globe from the frigid waters of the Arctic Circle to coral reefs in the tropical Central Pacific.
Much of his current research centers on the use of acoustic telemetry and satellite-based tagging technology to study the ecology and behavior of sharks.
He has written dozens of scientific research papers and has appeared in a number of film and television documentaries, including programs for National Geographic, Discovery Channel, BBC, and numerous television networks.
His most recent book, The Shark Handbook, is a must buy for all shark enthusiasts. Robert D. He served in the U. Navy for more than 30 years and continues to work with the Office of Naval Research. A pioneer in the development of deep-sea submersibles and remotely operated vehicle systems, he has taken part in more than deep-sea expeditions. In , he discovered the RMS Titanic , and has succeeded in tracking down numerous other significant shipwrecks, including the German battleship Bismarck , the lost fleet of Guadalcanal, the U.
He is known for his research on the ecology and evolution of fauna in deep-ocean hydrothermal, seamount, canyon and deep trench systems.
He has conducted more than 60 scientific expeditions in the Arctic, Atlantic, Pacific, and Indian Oceans. Sunita L. Her research explores how the larvae of seafloor invertebrates such as anemones and sea stars disperse to isolated, island-like habitats, how larvae settle and colonize new sites, and how their communities change over time. Rocks are good insulators so the heat has been slow to dissipate. This heat is enough to partially melt some rocks in the upper mantle, about km below the surface.
We say partially melt because the rocks don't completely melt. Most rocks are made up of more than one mineral, and these different minerals have different melting temperatures.
This means that when the rock starts to melt, some of the minerals get melted to a much greater degree than others. The main reason this is important is that the liquid magma that is generated is not just the molten equivalent of the starting rock, but something different.
You could think of making a "rock" out of sugar, butter, and shaved ice. If you start melting this "rock", however, the "magma" that is generated will be highly concentrated in the things that melt more easily, namely the ice now water and butter.
Several eruptions during the past century have caused a decline in the average temperature at the Earth's surface of up to half a degree Fahrenheit scale for periods of one to three years. The climactic eruption of Mount Pinatubo on June 15, , was one of the largest eruptions of the twentieth century and injected a million ton metric scale sulfur dioxide cloud into the stratosphere at an altitude of more than 20 miles. The Pinatubo cloud was the largest sulfur dioxide cloud ever observed in the stratosphere since the beginning of such observations by satellites in It caused what is believed to be the largest aerosol disturbance of the stratosphere in the twentieth century, though probably smaller than the disturbances from eruptions of Krakatau in and Tambora in Consequently, it was a standout in its climate impact and cooled the Earth's surface for three years following the eruption, by as much as 1.
The large Laki fissure eruption in Iceland released a staggering amount more sulfur dioxide than Pinatubo approximately million ton vs. Although the two eruptions were significantly different in length and style, the added atmospheric SO 2 caused regional cooling of Europe and North America by similar amounts for similar periods of time. Carbon dioxide CO 2 is a greenhouse gas and is the primary gas blamed for climate change. While sulfur dioxide released in contemporary volcanic eruptions has occasionally caused detectable global cooling of the lower atmosphere, the carbon dioxide released in contemporary volcanic eruptions has never caused detectable global warming of the atmosphere.
In , human activities were responsible for a projected 35 billion metric tons gigatons of CO 2 emissions. All studies to date of global volcanic carbon dioxide emissions indicate that present-day subaerial and submarine volcanoes release less than a percent of the carbon dioxide released currently by human activities.
While it has been proposed that intense volcanic release of carbon dioxide in the deep geologic past did cause global warming, and possibly some mass extinctions, this is a topic of scientific debate at present.
Published scientific estimates of the global CO 2 emission rate for all degassing subaerial on land and submarine volcanoes lie in a range from 0.
The gigaton projected anthropogenic CO 2 emission for is about 80 to times larger than the respective maximum and minimum annual global volcanic CO 2 emission estimates.
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