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Imaggeo

Imaggeo on Mondays: Moving images – Photo Contest 2016

Since 2010, the European Geosciences Union (EGU) has been holding an annual photo competition and exhibit in association with its General Assembly and with Imaggeo – the EGU’s open access image repository.

In addition to the still photographs, imaggeo also accepts moving images – short videos – which are also a part of the annual photo contest. However, 20 or more images have to be submitted to the moving image competition for an award to be granted by the judges.

This year saw seven interesting, beautiful and informative moving images entered into the competition. Despite the entries not meeting the required number of submissions for the best moving image prize to be awarded, three were highly ranked by the photo contest judges. We showcase them in today’s imaggeo on Mondays post and hope they serves as inspiration to encourage you to take short clips for submission to the imaggeo database in the future!


Aerial footage of an explosion at Santiaguito volcano, Guatemala. Credit: Felix von Aulock (distributed via imaggeo.egu.eu)

During a flight over the Caliente dome of Santiaguito volcano to collect images for photogrammetry, this explosion happened. At this distance, you can clearly see the faults along which the explosion initiates, although the little unmanned aerial vehicle is shaken quite a bit by the blast.


Undulatus asperitus clouds over Disko Bay, West Greenland. Credit: Laurence Dyke(distributed via imaggeo.egu.eu)

Timelapse video of Undulatus asperitus clouds over Disko Bay, West Greenland. This rare formation appeared in mid-August at the tail end of a large storm system that brought strong winds and exceptional rainfall. The texture of the cloud base is caused by turbulence as the storm passed over the Greenland Ice Sheet. The status of Undulatus asperitus is currently being reviewed by the World Meteorological Organisation. If accepted, it will be the first new cloud type since 1951. Camera and settings: Sony PMW-EX1, interval recording mode, 1 fps, 1080p. Music: Tycho – A Walk.

Lahar front at Semeru volcano, Indonesia. Credit: Franck Lavigne (distributed via imaggeo.egu.eu)

Progression of the 19 January 2002 lahar front in the Curah Lengkong river, Semeru volcano, Indonesia. Channel is 25 m across. For further information, please contact me (franck.lavigne@univ-paris1.fr)

 

Imaggeo on Mondays: Half dome at sunset

Imaggeo on Mondays: Half dome at sunset

Yosemite’s Half Dome stands, majestic, over a granite dominated terrain in the Yosemite Valley area;  one of the most beautiful landscapes in northern America, and arguably, the world – it is also an Earth scientist’ playground.

Stamped into the west slope of the Sierra Nevada range, the Yosemite Valley is a collection of lush forests, deep valleys, meandering rivers and streams, all punctuated by huge domes and cliffs of ancient volcanic origin.

Come and explore this part of the world and you’ll not miss Half Dome. Standing at the head of the valley, the quartz monzonite (a coarse grained orthoclase and plagioclase feldspar dominated rock) structure rises a little short of 2700 m above sea level.

Despite standing proud in the present landscape, it was once a magma chamber, buried deep below a volcano. Over a long period of time, the molten magma cooled and crystalised to form the coarse granite rock we see today. Erosion and exposure did the rest, eventually exhuming the dome and cutting deep valleys into the surrounding landscapes.

For more information on the geology of the Yosemite Valley and Half Dome, please refer to these United States Geological Survey (USGS) resources:

The Geological Story of Yosemite Valley
How did Half Dome, acquire its unique shape?
Bedrock Geology of the Yosemite Valley Area

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: Earth Wave

Imaggeo on Mondays: Earth Wave

Take a stroll along the norther beaches of the French Channel Coast, some kilometers east from the entrance of the Channel Tunnel, and you’ll encounter an imposing cliff of soft, sandy composition which dominates the landscape.

On close inspection, the sediments which make up the Quaternary aged deposits of the Sangatte Cliff, are beautiful, revealing intricate patterns which hold the key to the geological processes that formed them. Even at present, the landscape is being continuously shaped by marine processes which continuously erode the Quaternary soft deposits – especially during storms coupled with high tide events.

The Sangatte sedimentary sequence outcrops along a stretch of about 1.5 km along the French coast. Today’s featured image was taken by Pierre Antoine, at the base of the Quaternary sequence of the Sangatt Cliff. It corresponds to an observation window of about 80 cm large.

“At this location, explains Pierre, the Quaternary record is composed of raised beach deposits (flint pebble bar and sandy beach deposits, ± 3m thick) dating from a Middle Pleistocene interglacial (± 300 ka) and to a high sea level (± 5 m above the present day level), covered by a thick succession of chalky periglacial slope deposits, formed during periods of repeated freezing and thawing, associated with loesses and fossil soils know as palaeosols (8 to 12m).”

The greenish sandy deposits exposed at the base of the photo represent the top of the ancient marine beach deposits. These were overlain by a thin, dark bown, peat layer indicative of a phase of sea level drop. It is likely that during this time a peat bog, which was isolated from the sea by wind-driven sand dunes, developed .

This peat layer has, more recently, been strongly compressed and reworked during the deposition of the overlying thick bed of dense chalk mud. The greyish muds are the result of the weathering of the massive chalky slopes of the Sangatte Cliff,  which occurred following a cold period after the sea-level decrease. The delicate rusty bands seen in the otherwise creamy chalky muds, are the result of infiltration of iron oxide minerals throughout the cliff.

Reference:

Antoine, P. 1989. Stratigraphie des formations pléistocènes de Sangatte (Pas-de-Calais), d’après les premiers travaux du Tunnel sous la Manche. Bulletin de l’Association Française pour l’Etude du Quaternaire, 37, 5-17.

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: The waxing Earth

Imaggeo on Mondays: The waxing Earth

These incredible images of Earth were acquired from the European MSG-2 satellite on July 21, 2009. The MSG, which stands for Meteosat Second Generation, satellites are operated as a series of satellites which continually orbit our planet, capturing detailed images of Europe, Africa and parts of the Atlantic and Indian Ocean every 15 minutes. The data acquired is largely used by meteorologists.

The satellites operate in a geostationary orbit. This means they are located some 36000km above the equator and follow the Earth’s rotation. This orbit allows an extraordinary view on the waxing Earth at 5:00, 6:00, 7:00, 8:00, 10:00, and 12:00 UTC.

But what causes this periodicity ? Exploring the phases of our Moon over the period of approximately a month helps us visualise this phenomenon. It takes the Moon 27 days to complete a full revolution around Earth. During this time, the relative position between the Moon, Earth and the Sun changes, so that, seen from the Earth’s perspective, a new, waxing, full Moon, and waning Moon. Similarly, from the perspective of a geostationary satellite, the Earth apparently orbits the satellite once per day and likewise it observes a “new Earth”, “waxing Earth”, “full Earth”, and “waning Earth” once per day.

Interestingly, the MSG satellites have only one channel (covering the full earth disk) in the visible spectral region, in other words, the portion of the electromagnetic spectrum that is visible to the human eye. The human eye has receptors for three different colours, which means information is missing to generate true colour composite images from MSG. For this reason, Maximillian Reuter (a researcher at Institute of Environmental Physics, University of Bremen, in Germany) and Susanne Pfeifer (Climate Service Center Germany) developed an algorithm that primarily uses the SEVIRI (the main instrument aboard MSG) channels at 0.6μm, 0.8μm and 1.6μm, to transform RGB (red/green/blue) false colour composite images of the used channels into (quasi) true color images. The result is today’s featured image. The lack of information in the blue and green parts of the visible spectrum is compensated by using data from NASA’s Blue Marble next generation project.

By Maximillian Reuter, researcher at Institute of Environmental Physics, University of Bremen and Laura Roberts, EGU Communications Officer.

References :

More information in the publication M. Reuter, S. Pfeifer: Moments from space captured by MSG SEVIRI. International Journal of Remote Sensing, 32, 14, 4131-4140, doi: 10.1080/01431161.2011.566288,2011.

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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