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Publications by the EGU

10 May

The EGU is responsible for 14 Open Access journals, all freely available online

Since 2001, the EGU and Open Access publishing house Copernicus Publications has published a growing number of successful geoscientific journals. These include 14 peer-reviewed Open Access journals, of which 11 have a Thomson Reuters Impact Factor, placing them in the top echelon of their respective discipline. EGU also publishes a host of other materials available in paper and online. As a signatory of the Berlin Open Access Declaration (2003), the EGU is committed to making all their publications freely available.

The EGU’s Open Access scientific journals are:


EGU General Assembly 2012 Call for Papers

9 Nov

Abstract submission for the EGU General Assembly 2012 (EGU2012) is now open. The General Assembly is being held from Sunday 22 Apr 2012 to Friday 27 Apr 2012 at the Austria Center Vienna, Austria.

You can browse through the Sessions online.

Each Session shows the link Abstract Submission. Using this link you are asked to log in to the Copernicus Office Meeting Organizer. You may submit the text of your contribution as plain text, LaTeX, or MS Word content. Please pay attention to the First Author Rule.

The deadline for the receipt of Abstracts is 17 January 2012. In case you would like to apply for support, please submit no later than 15 December 2011. Information about the financial support available can be found on the Support and Distinction part of the EGU GA 2012 website.

Further information about the EGU General Assembly 2012 on it’s webpages. If you have any questions email the meeting organisers Copernicus.

Geosciences column: Iceland spar, or how Vikings used sunstones to navigate

2 Nov

Nowadays, we can rely on GPS receivers or magnetic compasses to tell us how to reach our destination. Some 1000 years ago, Vikings had none of these advanced navigation tools. Yet, they successfully sailed from Scandinavia to America in near-polar regions where it can be hard to use the Sun and the stars as a compass. Clouds or fog and the long twilights characteristic of polar summers complicate direct observations of these celestial bodies. So how did they find their bearings? A new study published in Proceeding of Royal Society A shows that they probably used Iceland spar, a “sunstone”.

Centuries-old Viking legends tell of glowing sunstones that navigators used to find the position of the Sun and set the ship’s course even on cloudy days. In 1967, a Danish archaeologist named Thorkild Ramskou speculated that the Viking sunstone could have been Iceland spar, a clear variety of calcite common in Iceland and parts of Scandinavia.

This crystal has an interesting property called birefringence: a light ray falling on calcite will be divided in two, forming a double image on its far side. (This double image is easily seen by placing transparent calcite on printed text.) Further, the Iceland spar is a polarising crystal, meaning the two images will have different brightnesses depending on the polarisation of light.

Birefringence of Iceland Spar seen by placing it upon a paper with written text. Source: Wikimedia Commons.

Light is made up of electromagnetic waves with component electric and magnetic fields. If these components have a specific orientation, the light is said to be polarised, while in unpolarised light the orientation of these fields has no preferred direction. Calcite can appear dark or light depending on the polarisation of light that falls upon it.

Sunlight becomes polarised as it crosses the Earth’s atmosphere, and the sky forms a pattern of rings of polarised light centred on the Sun. Changing the orientation of calcite as light passes through it will change the relative brightness of the projections of the split beams, even when the Sun is hiding behind clouds or just below the horizon. The beams are equally bright when the crystal is aligned to the Sun.

It can be hard to determine when exactly these split beams have equal brightness. But the new study, led by Guy Ropars at the University of Rennes 1 in France, suggests Vikings could have built a simple device to better use the sunstone.

The technique consists in covering the Iceland spar with an opaque screen with a small hole in its centre and a pointer. As light passes through the hole onto the crystal, a dark surface below it receives the projection of the double image for comparison.

The authors of the Proceedings of the Royal Society study believe Vikings could have used a device like this to navigate. The crystal is inside, and the projection of a double image is seen below it. Credit: Guy Ropars. Source: ScienceNOW.

By rotating the apparatus and determining the direction at which the two images were equal in brightness, the team managed to pinpoint the Sun’s position on a cloudy day with an accuracy of one degree on either side. Researchers also conducted tests when the Sun was largely below the horizon. “We have verified that the human eye can reliably guess clearly the Sun direction in dark twilights, even until the stars become observable,” Ropars’ team writes in the paper.

Although archaeologists have not yet found Iceland spar among Viking shipwrecks, the new study adds credence to the idea that Viking seafarers used the crystal in their travels.

Further, the recent finding of a calcite crystal on a sixteenth century Elizabethan ship shows that navigators could have used Iceland spar even after the appearance of the magnetic compass. Cannons on ships could perturb a magnetic compass orientation by 90 degrees, so a crystal serving as an optical compass could be crucial in avoiding navigational errors and get sailors to a safe port.

By Bárbara Ferreira, EGU’s Media and Communications Officer

Call for Sessions for EGU General Assembly 2012

8 Jul

The public call for sessions for the European Geosciences Union General Assembly 2012 has been issued. The EGU GA 2012 will be held at the Austria Center Vienna (ACV) from 22 April to 27 April 2012. The details are below, the web page to visit to submit sessions is Call for Sessions page of the EGU General Assembly 2012 website.

We hereby invite you, from now until 16 Sep 2011, to take an active part in organizing the scientific programme of the conference.

Please suggest (i) new sessions with conveners and description and (ii) modifications to the skeleton programme sessions. Explore the Programme Groups (PGs) on the left hand side, when making suggestions. Study those sessions that already exist and put your proposal into the PG that is most closely aligned with the proposed session’s subject area.

If the subject area of your proposal is strongly aligned with two or more PGs, co-organization is possible and encouraged between PGs. Only put your session proposal into one PG, and you will be able to indicate PGs that you believe should be approached for co-organization.

If you have questions about the appropriateness of a specific session topic, please contact the Officers for the specific EGU2012 Programme Group. To suggest Union Symposia, Great Debates, Townhall Meetings or Short Courses, please contact the Programme Committee Chair (Gert-Jan Reichart).

In case any questions arise, please contact EGU2012 at Copernicus.