Between a Rock and a Hard Place

Science snap

Science Snap (#15): Big freezes

Satellite image of North America's Big Freeze, January 2014. Image credit: BBC

Satellite image of North America’s Big Freeze, January 2014. Image credit: NASA

Satellite images are not just wonderful for science, they also capture public interest during periods of intense and news grabbing weather. Earlier this month North America was gripped by a prolonged Arctic Chill, plunging the continent into freezing temperatures and smashing temperature records in the process. Consecutive satellite images tracked the southward progress of the freezing continent that looked unnervingly like the scenes from The Day After Tomorrow

The UK hasn’t been exempt from similar chills. Remember the winter of 2010 anyone!?

Satellite image of the UK's big freeze, November-December 2010. Image Credit: the Met Office

Satellite image of the UK’s big freeze, November-December 2010. Image Credit: the Met Office

Science snap (#14): San Andreas Fault

San Andreas fault

Historic fence line on the San Andreas Fault showing relative movement during the 1906 earthquake. Credit: Charly Stamper

As one of ~20,000 geologists flocking to AGU Fall Meeting in San Francisco, I’ve headed out a few days early to take in a few West Coast sights. For many, the Foggy City will always be synonymous with earthquakes. San Francisco is located right on the San Andreas Fault, which is part of a larger fracture zone marking the boundary between the North American and Pacific tectonic plates. In 1906, a sudden release of stress along the San Andreas Fault resulted in a magnitude 7.8 earthquake. The city of San Francisco was ravaged by fire and over 3,000 people lost their lives. Along the fault suture, the north-west moved 6m relative to the south-east, a feature preserved in historic fence lines. More recently, the fault was responsible for the devastating 1989 Loma Prieta quake. Nobody knows when the next ‘big one’ is due, but there is no doubt that seismic activity will continue to be felt in this area. A small shake would probably go down quite well with the visitors in town!

Science snap (#12): Purple bacteria

KT Cooper is a PhD student in the School of Earth Sciences at the University of Bristol. A carbonate geochemist by training, she has just returned from a three-month secondment to Houston, Texas, USA working with Exxon Mobil.

The world of microbiology is weird, wonderful and also quite multi-colourful. Purple bacteria, a particular hue of microbe which holds a special place in my heart, have just taken the spotlight when it comes to the search for life on other planets. These bacteria were known to dominate life on the early Earth, around 3 Ga ago, and can survive on land and in water.

Water sample full of purple bacteria taken from a blue hole on North Andros as part of my PhD research, courtesy of Didi Ooi

They produce their energy through photosynthesis, like plants, and it has been suggested they could be used to harvest solar energy (highly efficient solar panels could utilise the bacteria’s natural ability to adapt to varying light intensities). They also have a highly reflective nature and it is this that has been proposed to be used in the hunt for life on other planets.

An extensive research effort exists to investigate how Earth might look like from distant observers so that we maybe able to identify other planets out there that could harbour life. Many different remote sensing and imaging techniques are being used but the research is not only focused on the Earth as it is now, but also as how it may have looked in a more primitive state. Computer models have been used to investigate if the Earth were covered in purple bacteria how this may be imaged from space. This research hopes to help identify life, albeit less little green men and more really little purple bacteria, on other planets.

Science Snap (10): The impact of eruptions

Mel Auker brings us our Science Snap this week…

Many people are aware of the May 1980 eruption of Mount St. Helens in Washington State, USA. Common photographs of the huge VEI 5 eruption show the large, billowing eruptive column rising into the stratosphere.

Less iconic are images of the destruction left behind, demonstrating the after-effects of the eruption. The US president at the time, Jimmy Carter, flew over St. Helens soon after and said the area looked “more desolate than a moonscape.” Now, more than 30 years on, the landscape still displays reminders of the awesome power of nature. Below are a selection of photographs taken in August 2011.

From top left, clockwise: 1. “Miner’s Car”, the remains of a car situated approximately 15 km from the volcano at the time of the eruption; 2. Trees flattened by the debris flow; 3. Tree trunks in Spirit Lake, approximately 8 km north of the volcano; 4. Hummocky avalance deposits. Credit: Melanie Auker

The top left photograph is of “Miner’s Car“, which has been left in place as a monument approximately 15 km NE of St. Helens. The heat of the eruption burnt all the exposed paint off the car, though the bumper (at the right of the image) is still largely undamaged. The top right photograph shows large trees flattened by the eruption, mantling the topography and identifying the direction of flow.

The bottom left photograph shows the huge number of tree trunks present in Spirit Lake, approximately 8 km north of St. Helens. As well as flattening trees, the eruption tore thousands from the ground which were deposited in the lake. The volume of material emplaced in the lake has reduced its surface elevation by over 60 m. The bottom right photograph depicts the rounded mounds (hummocks) that form part of the debris avalanche deposit to the north of the volcano. They are formed of relatively intact rocks that once formed the volcano’s summit.