GeoLog

Imaggeo on Mondays

Imaggeo on Mondays: Breath from the underground

Imaggeo on Mondays: Breath from the underground

The heat seeping from the geothermal area which is part of the Krafla volcanic system in Iceland, ‘powers’ the steaming vent at Hverir (Hverarönd). The area is well known for its mud pots and sulphuric gas fumaroles, complete with pungent eggy smell.

Some of the vents are in fact boreholes drilled in the 50’s for sulphur exploration which have been turned into fumaroles, the steam is a result of a steam zone above boiling groundwater. High temperature geothermal areas are a byproduct of Iceand’s volcanic setting and the energy released can be used to power homes and infrastructure. Indeed, geothermal power facilities currently generate 25% of the country’s total electricity production. You can read all about that in an Imaggeo on Mondays we published a couple of months ago.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: Airplane views of the Alps

Imaggeo on Mondays: Airplane views of the Alps

The forward scattering of sunlight, which is caused by a large number of aerosol particles (moist haze) in Alpine valleys, gives the mountain massifs a rather plastic appearance.

The hazy area in the foreground lies above the Koenigsee lake; behind it the Watzmann, Hochkalter, Loferer Steinberge and Wilder Kaiser massifs loom up behind one other to the right of the centre line. Behind them is the wide Inn valley, which extends right across the picture. In the far distance in the middle of the picture, the Wetterstein massif projects upwards with the Zugspitze mountain as its highest peak.

The left side shows Steinernes Meer, Leoganger Steinberge and a sequence of at least 10 mountain chains that extend as far as Kellerjoch, which is in front of the whitish area of haze above Innsbruck. The noon sounding from Munich showed that relative humidity exceeded 75% up to 1,400 m above sea level, with distinctly lower values above (less than 20 %).

The view is from an aircraft window approximately 10 km to the east of the Salzach valley.

Description by Hans Volkert, as published previously on imaggeo.egu.eu

Imaggeo on Mondays: Erebus Ice Tongue Cave

Imaggeo on Mondays: Erebus Ice Tongue Cave

The interior of this ice cave at the Erebus glacier tongue is cathedral-like. Imagine standing in the cold interior, icy blue stalactites dangling from the cave roof; the sense of awe is overwhelming.

Mt. Erbus is the world’s southernmost active volcano on Ross Island, in Antarctica. Winding its way down its lower slopes is Erebus glacier. Projecting out from the coast, a jagged and thin tongue makes its way into the ice-covered Ross Sea.

The interplay of glacial flow and tides leads to scalloped edges of the tongue where ice caves commonly form. Due to surface melting in the Antarctic summer the interior is filled with intricate icicles and ice crystals.

 

Erebus Ice Tongue. NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and the U.S./Japan ASTER Science Team.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

Imaggeo on Mondays: Natural Bridges Monument, Utah, USA

Imaggeo on Mondays: Natural Bridges Monument, Utah, USA

Slowly but surely, the force of water has carved out a beautiful landscape in the sandstones of the Colorado Plateau. Suspended over canyons, naturally formed bridges and arches are the starts of Utah’s first national monument. The geological and modern  history of the region is rich as Kimberly Galvez, a student of the University of Miami, describes below.

This image shows an overview of a portion of the Natural Bridges Monument in Utah, taken from the Colorado Plateau. In the lower center of the picture is the Sipapu Bridge, one of the 3 bridges within the national park.

The dominating sandstone comes from the Permian Cedar Mesa Formation that is part of the Colorado Plateau, a geologic province that extends through southern Utah and northern Arizona, northwest New Mexico, and western Colorado; with geologic units including the Lower Cutler Beds from the Pennsylvanian, Permian Organ Rock and Cedar Mesa Formation, Triassic Chinle and Moenkopi Formations, Jurassic Wingate Sandstone and the Quaternary alluvium.

Due to the regional uplift the Colorado Plateau experienced, meandering rivers progressively cut through the crossbedded sandstone – cross-bedding reflects the transport of sand by a flow of water over a river channel – of the Cedar Mesa Formation forming the bridges, leaving behind the exposed erosional surfaces carved out by the river.

Today, these bridges face many challenges: The region is still seismically active. Earthquake activity could lead to the collapse of (some of) the bridges and other small formations. Due to the low stability of the sandstone from the lack of anchoring from root structures, slope failures and slumps can be quite common and especially in the event of flash floods. Continuous wind patterns increase erosion and alter the exposed surfaces and the structure of the channel is constantly changing due to seasonal rainstorms.  Sediment transport and deposition, caused by streamflow, is a major factor in channel morphology and, therefore, the ecosystem of the Natural Bridges Monument.  The National Park Service constantly monitors the changes and issues that arise.

A final remark: Thanks to the entire group of the 2015 Annual AAPG Student Field Trip for making this photo possible. Members of the CSL – Center for Carbonate Research and the UM Student Chapter of AAPG for funds, and field trip leaders: Gregor Eberli and Donald McNeill.

By Kimberly C. Galvez, University of Miami – RSMAS

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

 

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