GeoLog

Imaggeo on Mondays

Imaggeo on Mondays: Waves hitting Cycladic rocks

Rocks and Sea Waves in Andros Island, Greece by Ioannis Daglis, distributed by EGU under a Creative Commons licence.

Rocks and Sea Waves in Andros Island, Greece by Ioannis Daglis, distributed by EGU under a Creative Commons licence.

When he is not researching in the space sciences, Ioannis Daglis, the director of the Institute for Space Applications and Remote Sensing at the National Observatory of Athens in Greece, is often out with his camera. This picture of sea waves slamming cliff rocks in the Aegean Sea is a beautiful example of his artistic work, and one that shows some science too.

“I took this photo at Vitali Bay in the island of Andros in the Greek Cyclades during a summer vacation in August 2007. It shows a cliff made irregular by wave erosion, tectonic activity or both. It consists mainly of metamorphic rocks such as schists, phyllites and marbles. These are typical geologic formations that constitute 75% of the total coastline of the island since Andros is mainly covered by metamorphic formations,” Daglis explained.

The Cyclades is a geologically rich group of some 220 islands. The dormant volcano of Milos, the famous Santorini caldera, and the hot springs in Kythnos are examples of geological sites worth a visit.

Daglis’ geosciences-related photographs, taken in Greece and elsewhere, are featured on Imaggeo.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Imaggeo on Mondays: Zurich lit by lightning

Zurich lit by lightning by Ryan Teuling, distributed by EGU under a Creative Commons licence.

Zurich lit by lightning by Ryan Teuling, distributed by EGU under a Creative Commons licence.

In Zurich, Switzerland, June is often the wettest month of the year. Summer thunderstorms that give clouds a purple-grey colour and bright up the skies with strong lightning bolts are common place. This picture, taken by Ryan Teuling from Wageningen University in the Netherlands, captures one of these bolts, lighting up the centre of the city.Teuling took this photo in June 2008 when he worked at the Institute for Atmospheric and Climate Science (CHN) in Zurich, following the Institute’s yearly barbecue.

“From the upper floor of the CHN building we had a great view of the centre of Zurich, the lake, and the active lightning. The lightning was so intense that I could take the picture by controlling the shutter by hand in response to lightning flashes, and not in automatic or repeat mode,” Teuling said. The storm front was stationary over Lake Zurich, visible in the centre of the frame, he added.

Thunderstorms occur when warm, moist air rises rapidly upwards, cools and condenses forming clouds and water droplets. These strong convective cells of air develop easily in the diverse topography of Zurich, a city located in a valley in the north tip of Lake Zurich, near the Albis chain of hills.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Imaggeo on Mondays: El Tatio geyser field

El Tatio Geyser Field by Simon Gascoin, distributed by EGU under a Creative Commons licence.

El Tatio Geyser Field by Simon Gascoin, distributed by EGU under a Creative Commons licence.

Excursions following scientific conferences often give researchers a chance to observe geosciences phenomena in remote areas. That was the case for Simon Gascoin, from the Centre d’Etudes Spatiales de la Biosphère in Toulouse, France who got to photograph geysers in a Chilean desert after the EGU Alexander von Humboldt conference in Santiago de Chile in late 2008.

“The picture shows the El Tatio geyser field, located at 4,200 metres above sea level, in the hyperarid Atacama desert. Steam columns and boiling water are caused by the high geothermal fluxes in this volcanic region, which heat the groundwater,” Gascoin explained.

The El Tatio geyser field is the largest geyser field in the southern hemisphere with no less than 80 active geysers. Eruptions of groundwater heated by magma at El Tatio have an average height of 75 centimetres, but the record steam and water jet reached some six metres above ground.

The Chilean Government declared the field a protected area in 2010.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Imaggeo on Mondays: Huts in Arcachon Bay

The Tchanquees Huts in the Arcachon Bay by Yann Vitasse, distributed by EGU under a Creative Commons licence.

The Tchanquees Huts in the Arcachon Bay by Yann Vitasse, distributed by EGU under a Creative Commons licence.

Yann Vitasse, now a researcher at the Institute of Botany, University of Basel in Switzerland, got a wonderful present in 2009 for completing his PhD: a flight on an ultralight aircraft above the southwest coast of France. It was then he took this stunning photo of the Arcachon Bay, a water area near Bordeaux that is fed by the Atlantic Ocean and by a number of fresh waterways.“Here you see the famous Tchanquees Huts which were built on stilts in the middle of the Arcachon Bay, on the bird island. These huts were originally used for monitoring oyster beds,” Vitasse said.

The photo was taken at low tide, a time when the water covers an area of only 40 square kilometres. By comparison the bay takes up some 150 square kilometers at high tide, when the entire area to the left of the huts is covered by sea water.

The bird island, starting to the right of the huts, also varies in area being some 10 times larger at low tide. Geologists are still out on the origin of this structure. Some defend it is a former sandbar while others prefer the theory that it formed from the remains of a high dune shaped by the wind and the ocean.

Imaggeo is the online open access geosciences image repository of the European Geosciences Union. Every geoscientist who is an amateur photographer (but also other people) can submit their images to this repository. Being open access, it can be used by scientists for their presentations or publications as well as by the press. If you submit your images to imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.