Studying Climate Variability By Reconstructing 2500 Years Of Volcanic Activity

Scientists from the Desert Research Institute (DRI) and other institutions reconstructed 2500 years of volcanic activity to prove that volcanic eruptions contribute to climate variability. Gathering data from eruptions dating as far back as the Roman Era, the scientist published a study associating these with extreme shifts in the climate.

The study notes that eruptions in the tropic and high latitudes were primary contributors of climate variability. These were caused by large amounts of volcanic sulfate particles injected into the upper atmosphere which blocked incoming solar radiation from reaching the Earth's surface. The scientists also studied tree rings from long living bristlecone-pines and saw indications for extreme cooling after a large volcanic eruption. The same results were also derived from looking at ice cores from Greenland (see image above).

The study also shows that between 500 BC and 1000 AD, 15 of the 16 coldest summers followed large volcanic eruptions; four of them happening just after the largest volcanic events found in record.

Hochstetter's Butterfly-orchid, Europe's Rarest Orchid, Found in the Azores

A research team of botanists have discovered Narrow-lipped Butterfly-orchid (P. micrantha) which was last seen in 1844. This species of orchids was found in the highest volcanic ridge on the central island of São Jorge in the Azores islands.

Previously, there were only two species of orchids known to inhabit the Azores and the discovery of this third butterfly orchid, which was documented by German botanist Karl Hochstetter 173 years ago and never seen again, urgently requires conservation recognition.

The Hochstetter's Butterfly-orchid is threatened by habitat destruction and invasive alien plants.

The Azores is made up of nine volcanic islands in the middle of the northern hemisphere of the Atlantic Ocean. It is situated west of Portugal (around 1,360 kilometers or 850 miles). It is also 1,510 kilometers (940 miles) northwest of Morocco, and about 1,925 km (1,196 mi) southeast of Newfoundland.

The islands were formed through volcanic and seismic activity around 8 million years ago during the Neogene period.

Each of the nine islands have unique and distinct geomorphological characteristics which sets it apart from each other; ranging from Corvo which is a crater formed from a major Plinian eruption to the almost circular Terceira which has one of the largest craters in the region. The largest island is São Miguel which has many large craters and fields of spatter cones.

Scientists Use X-Rays To Probe Origin of Volcanic Hotspots

A volcanic hotspot is a region where the mantle of the Earth is hotter than the mantle elsewhere. The mantle is the layer of the Earth between the crust and the outer core. The Earth's mantle is a rocky shell about 2,900 km (1,800 mi) thick and constitutes about 84% of Earth's volume.

There is a theory that volcanic hotspots exists because of the rising narrow streams of hot mantle from the Earth's core-mantle boundary in a structure called a mantle plume.

This is still a theory but scientists may have strong evidence to back it up.

This is an illustration showing how the mantle plumes can be emitted from the core-mantle boundary region to reach the Earth's crust. Due to the lateral displacement of the tectonic plates at the surface, the mantle plumes can create a series of aligned hot spot volcanoes. A mid ocean ridge and a subducted plate are also shown.
Credit: ESRF/Denis Andrault/Henri Samuel

X-rays illuminate the origin of volcanic hotspots

Scientists have recreated the extreme conditions at the boundary between Earth's core and its mantle, 2,900 km beneath the surface. Using the world's most brilliant beam of X-rays, they probed speck-sized samples of rock at very high temperature and pressure to show for the first time that partially molten rock under these conditions is buoyant and should segregate towards the Earth's surface. This observation is a strong evidence for the theory that volcanic hotspots like the Hawaiian Islands originate from mantle plumes generated at the Earth's core-mantle boundary. The results are published in Nature dated 19 July 2012.

The group of scientists was led by Denis Andrault from the Laboratoire Magmas et Volcans of University Blaise Pascal in Clermont, and included scientists from the CNRS in Clermont and the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.

Most volcanoes are situated where continental plates are pushed or pulled against each other. Here, the continental crust is weakened, and the magma can break through to the surface. The Pacific "Ring of Fire", for example, exhibits such plate movements, resulting in powerful Earthquakes and numerous active volcanoes.

Coiling Spiral Patterns Found In Mars Lava Flow

Hi Res Image of  Mars Lava Flow

The planet Earth is bigger than Mars, about two times the diameter of Mars. While nearly 70% of Earth is covered with liquid water, Mars has no visible water at all. Although Mars is said to have had liquid water at one time in its early years.

Despite the differences, Mars is similar to Earth, geologically, than any other planet in the solar systems. It has valleys and mountains, weather and seasons, and volcanoes and ice caps. At 24 hours and 39 minutes, the Martian day is only a little bit longer than Earth's. Because of these similarities, studying some geographical features in Earth helps scientists know more about Mars.

New form of Mars lava flow dicovered

High-resolution photos of lava flows on Mars reveal coiling spiral patterns that resemble snail or nautilus shells. Such patterns have been found in a few locations on Earth, but never before on Mars. The discovery, made by Arizona State University graduate student Andrew Ryan, is announced in a paper published April 27, 2012, in the scientific journal Science.

The new result came out of research into possible interactions of lava flows and floods of water in the Elysium volcanic province of Mars.

"I was interested in Martian outflow channels and was particularly intrigued by Athabasca Valles and Cerberus Palus, both part of Elysium," says Ryan, who is in his first year as a graduate student in ASU's School of Earth and Space Exploration, part of the College of Liberal Arts and Sciences. Philip Christensen, Regents' Professor of Geological Sciences at ASU, is second author on the paper.