Feeds

Svalbard overtakes medieval summers

Fat algae suggest record temperatures

High performance access to file storage

The so-called “Medieval Warm Period” may not have been as warm – and certainly not as uniformly warm – as is commonly believed, according to research led by Columbia University’s Lamont-Doherty Earth Observatory.

While the research only covers a small area – Norway’s Svalbard archipelago in the north – but the researchers believe the area is now clearly warmer than it was in the period from 950 to 1250 AD, known as the “Medieval Warm Period”.

“Our record indicates that recent summer temperatures on Svalbard are greater than even the warmest periods at that time,” says Colombia researcher William D’Andrea, lead author of the study. Right now, he believes, the region is experiencing its highest temperatures in 1,800 years.

The temperature reconstruction is based on an analysis of algae deposited in sediments in the eastern Svalbard lake called Kongressvatnet. As D’Andrea explains, these provide a more continuous weather record than ice cores. The algae are deposited continuously, whereas ice cores only preserve cold-season snowfall (and thus are an indication to winter, rather than summer, temperatures).

The marker in the algae the researchers look for is in the balance of saturated and unsaturated fats they algae lay down. To cope with colder water, they produce more saturated fats; in warmer water, the balance swings to unsaturated fats.

Samples collected in the Kongressvatnet lake cores were dated against the glass sediments left behind by known volcanic eruptions in the years 170 (Snæfellsjökull), 1104 (Hekla) and 1362 (Öræfajökull).

While there’s no doubt that the combination of a solar maximum and volcanic activity drove the medieval climate, D’Andrea’s assertion is that it wasn’t as uniform a warming as is widely believed. While parts of the Northern Hemisphere were hotter than today, the Svalbard record indicates that the region is getting summers 2 to 2.5°C hotter than in the period 950-1250 AD.

Svalbard’s more recent warming seems to reflect a complex set of drivers, the researchers suggest. In the year 1600, the West Spitsbergen Current of the Gulf Stream seems to have brought more tropical water to the area; warming began to accelerate further since 1890, and scientists attribute most of the warming since 1960 to human activity.

The study is published on Geology (abstract). ®

High performance access to file storage

More from The Register

next story
IBM Hursley Park: Where Big Blue buries the past, polishes family jewels
How the internet of things has deep roots in the English countryside
Video games make you NASTY AND VIOLENT
Especially if you are bad at them and keep losing
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Honeybee boffin STINGS OWN WEDDING TACKLE... for SCIENCE
Not the worst place to be stung, says one man
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.