Geology

Every 100,000 years a "super-eruption" of a major volcanic system occurs - one of the most catastrophic natural events on Earth - yet it's hard to know what triggers these violent explosions. The eruption of super-volcanoes dwarfs the eruptions of recent volcanoes and can trigger planetary climate change by inducing Ice Ages and other impacts. One such event was the Huckleberry Ridge eruption of present-day Yellowstone Park about two million years ago, which was more than 2,000 times larger than the 1980 eruption of Mount St. Helens in Washington. These super-eruptions are second only to…

You can thank the stretching of continents and the oceans that filled those newly created basins for the Earth we know today.  Rifting is one of the fundamental geological forces that have shaped our planet. But rifting involves areas deep below the Earth's surface so scientists have been unable to understand fully how it occurs. What is known is that with rifting, the center of the action lies in the lithosphere, which makes up the tectonic plates and includes the crust and part of the upper mantle. A paper in Science now provides us with the highest-resolution picture of the…

Using one of the most sensitive neutrino detectors on the planet, the Borexino instrument, an international team are measuring the flow of solar neutrinos reaching Earth more precisely than ever before.  Writing in the current issue of Physical Review Letters, they state  that the Borexino instrument has now measured with high precision the flux of the beryllium seven (7Be) solar neutrino, abundant, low-energy particles once below the observable threshold. With this advance, they can now precisely study the behavior of solar neutrinos with kinetic energy below 1 megaelectron volt (…

Mountains sure aren´t what they used to be. Take  the Dolomites in the Veneto Region of Italy and Austria; 140 to 90 million years ago, they were part of the sea floor rather than mountains.  Over millions of years, deposits were then formed from calcareous shells of marine life from the Mesozoic era. Tectonic forces later caused these sediments to rise upward to the mountaintops of today´s well-known and popular Southern Alps. The mountain range contains one of the most complete and most accessible geological records - also being one of the richest in fossils - from the Cretaceous…

Rocks collected from the Franklin Mountains in West Texas and Coats Land in Antarctica have the exact same composition of lead isotopes, according to new research, the strongest evidence yet that parts of North America and Antarctica were connected 1.1 billion years ago, long before the supercontinent Pangaea formed. Earlier analyses showed the rocks to be the exact same age and have the same chemical and geologic properties. The new work in Geology strengthens support for the so-called SWEAT hypothesis, which posits that ancestral North America and East Antarctica were joined in an…

Almost a year ago I started my PhD with fieldwork on Santorini, Greece.  As I am currently planning a second round of fieldwork, I though it was time to write up my first trip. I have already written a short introduction to Santorini, as well as a more detailed look at the geology.  In this post, however, I wanted to take a more personal look at the island; what my work is about and what it is like to visit these places as a scientist.  I also have some pretty photos that I would like to show. I spent three weeks on the island.  The first few days were spent being shown…

44 trillion watts of heat continually flow from Earth's interior into space. Where does it come from? Researchers can say with 97 percent certainly that 50 percent of the heat is due to radioactive decay and other sources, like primordial heat left over from the planet's formation, must account for the rest. Knowing that radioactive decay of uranium, thorium, and potassium in Earth's crust and mantle is a principal source, in 2005 scientists in the Kamioka Liquid-scintillator Antineutrino Detector (KamLAND) collaboration first showed that there was a way to measure the contribution directly…

Have a computer?  Of course you do, or you aren't reading this article.   That, and a little space on your floor can make you a 'citizen seismologist.' The Quake Catcher Network is 6,000 tiny sensors, part of the densest networks of seismic sensors ever devoted to studying earthquakes, and it began rolling out in the San Francisco Bay Area where volunteer installers delivered 200 sensors to people who signed up to host them. The researchers were interested in locating sensors near the Hayward Fault, which runs roughly northwest-southeast through the East Bay, because it is…

Here's a question. In many millions of years time, is it possible that future geologists - be they our distant descendants, or an alien race that has since conquered Earth - will be able to look at the sequence of rocks corresponding to the present period, and recognise the moment when humans became the dominant species on the planet? If so, what time will this horizon represent, and how will it be recognised? This is the debate that is currently raging between stratigraphers worldwide. The concept is relatively simple - that humans have stuck their oars into so many natural processes that…

A recent BBC docu-drama called 'Atlantis' recreated the last days of the Bronze Age civilisation on the island of Thera (now known as Santorini), that I've meant to blog about for a while now.  This program, along with a more traditional 'Timewatch' documentary, argued that the eruption in roughly 1600 B.C. formed the foundation of Plato's description of Atlantis.  For me, however, the more interesting part of the program was their recreation of the eruption itself, an eruption so powerful it likely caused the downfall of the civilisation after which it is named: the Minoans. Before…