The Earth Story

The three worlds at Alta

From about 4000 BC the smooth cliffs around the Alta Fjord in Northern Norway were the setting of petroglyphs carved by hunter-gatherers living in this area. The petroglyphs (6000 in total) have a great variety in subject and are of special interest because the numerous native animals that are depicted. There are hardly any ethno historical sources about these prehistoric carvings and this makes it hard to discover their background and true meaning. Many scholars have argued that the Alta petroglyphs could be the first signs of a Nordic religion in the area. Around 500 BC the last carvings were made at Alta.

Most commonly depicted are elk (different from the North American elk, the European elk is actually a moose). Furthermore other native animals as bear, reindeer and wolf are depicted as well as human scenes and boats. Most carvings have a storytelling theme. As the image shows red colorants were used for relief.

Scholars have claimed that the location of the petroglyphs on steep cliffs near the sea could represents the Old Nordic belief in a world is divided in three parts; the sky being the upper world, the earth being the middle and the water being the lowest world. The location of the carvings at the shore could mark a contact zone between these worlds and the depicted animals could then be seen as vessels for travelling to the under and the upper world. .

So how is the rock art dated? After the last Ice age on the Scandinavian mainland, new land was exposed and smoothed cliffs appeared along the Norwegian coast. The land started to rise due to loss of pressure from the weight of the former ice, and these cliffs were lifted above sea level. From about 6000 to 7000 years ago nothing happened in relation to the sea and the land and the sea eroded the same cliffs for a long period. The rock carvings were made after this erosion so they cannot be much older than 6000 years. This dating method showed that the oldest carvings are found on higher altitudes whilst the cliffs that were coming out of the sea were used for new carvings.

In 1985 the site of Alta was placed on the UNESCO world Heritage list.

--BO

Image: Karl Brodowsky. A carving of a group of elk at Alta.

References:

Shetelig Haakon & Falk Hjalmar, Scandinavian Archaeology, The Art of the Arctic Stone Age, Oxford: Clarendon Press, 1937.

http://www.alta.museum.no/sider/tekst.asp?side=22&meny=ROCK+ART

http://www.verdensarvenialta.no/english/container3.htm_ _

Mosses live long and prosper! (Couldn't resist)

Biologists have reported that even after years of being buried under thick glacial ice, mosses can regrow!

The research group focused on plants from Canada’s Ellesmere Island, where the Teardrop Glacier has retreated since the end of a cold period in 1550 to 1850 known as the Little Ice Age. Among what seemed like dead mosses in an area that was newly exposed, the team from the University of Alberta noticed a few sprinkles of green.

Intrigued by this discovery, the group brought the sample back to the lab for testing. Using radiocarbon dating, they discovered that the moss had lived about 400 years ago. They also estimated, based on the glacial retreat rate, that the plants had been uncovered for less than two years.

They decided to make the plants feel at home, offering them some basic nutrients, some water and of course, light. From seven of the 24 samples, a total of four moss species grew.

Exactly how long a moss cell can stay viable is uncertain. But the findings suggest that the regenerated mosses may help repopulate ecosystems after glaciers retreat.

The report was published on the 27th of May in the Proceedings of the National Academy of Sciences.

For more information, see here: http://news.mongabay.com/2013/0527-dimitrova-ice-plants.html

-Jean

Ancient Mariners

Using radiocarbon dating (of Carbon-14 from nuclear test bombs set off in the oceans during the 1950’s; which reached the North Atlantic by the early 1960’s, via ocean food webs) within the eye lens nuclei from 28 females obtained as by-catch by fishermen, as a time marker, researchers recently released data regarding the life spans of the relatively unstudied Greenland sharks.

Living in the icy waters of the Arctic, the Greenland shark grows very slowly. Reaching more than 5 m (16.4 ft.) at maturity, the smallest sharks in the study (< 2.2 m or 7.2 ft. in length) were the only ones who showed evidence of the marker left by the bomb pulse. Further, the data revealed that the sharks did not reach sexual maturity until 156 ± 22 yrs. of age and that the largest female, at 5.02 m (16.5 ft.) was 392 ± 120 yrs. old.

Other scientists remain skeptical at the claim that the Greenland sharks are the longest-lived vertebrates on the planet (The longest life span of a marine organism thus far, is the ocean quahog, at 507 yrs., calculated via the annual growth rings on its shell), feeling that much more research needs to be done before forming a conclusion. CW

Image source

http://n.pr/2aOlYTt

Sources

http://science.sciencemag.org/content/353/6300/702

http://n.pr/2aOlYTt

The Shigir Idol

The world's oldest wooden sculpture is a 5.3 meter (17.4 ft) tall monument, cut from a single larch tree; a stylized face glares down from its top, and geometric patterns with other faces clothe its body. Dredged from a Siberian peat bog in 1890, the Shigir Idol was originally dated to 9,500 years ago using radiocarbon analysis, but reanalysis in 2015 revealed that the true age was 11,000 years old - 6,000 years older than Stonehenge and and twice the age of the pyramids. The preservation of the monumental piece is due to the anoxic (oxygen-poor) conditions in peat bogs, which prevent decomposition. Removal from the bog proved to be more tumultuous than the preceding millenia; a 2 meter section of the original artifact was lost sometime during Russia's political upheavals in the 20th century, though sketches remain. While part of the sculpture has been lost, what remains is a magnificent example of some of the world's most ancient art. -CEL

Source: http://bit.ly/1EsDebk Image: http://bit.ly/1EsDebk

New Study Improves Radiocarbon Dating A new study on sediments from Japan’s Lake Suigetsu is allowing scientists to make more accurate radiocarbon dating measurements. The study, part of an international effort to study past climate and environmental change, led by Professor Takeshi Nakagawa of Newcastle University and Professor Christopher Ramsey of the Oxford Radiocarbon Accelerator Unit, is using well preserved sediment cores from the lake that have been undisturbed for tens of thousands of years. Radiocarbon is continuously produced in the upper atmosphere; leading to near constant levels that plants and animals take in. When this plant/animal dies, the radiocarbon is no longer being absorbed and decays at a known rate, giving scientists the ability to date this organic material. The Lake Suigetsu sediments allowed the scientists to extend the record of atmospheric radiocarbon to 52,800 years, beating the previous tree ring dates of 12,593 years, by some 40,000 years. -AW Sources/Further Reading http://esciencenews.com/articles/2012/10/18/time.capsule.japanese.lake.sediment.advances.radiocarbon.dating.older.objects http://phys.org/news/2012-10-time-capsule-japanese-lake-sediment-radiocarbon.html http://www.sciencedaily.com/releases/2012/10/121018141834.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily+%28ScienceDaily%3A+Latest+Science+News%29 Image Credit: Richard Staff

The painting and the bomb This image shows the painting Contraste de Formes (Contrast of forms) by French artist Fernand Léger. The original painting was composed in 1913 as part of a series of paintings showing these sorts of abstract shapes. This particular painting was purchased by American art patron Peggy Guggenheim and placed in the collections of that museum. However, in the 1970’s, scholar Douglas Cooper suggested that the painting owned by the Guggenheim was a forgery. Afterwards, scholars were unable to agree on the authenticity of the work and so it was not displayed. Research done by the Italian Institute for Nuclear Physics has actually answered that question. In the 1950s and early 1960s, the United States and the Soviet Union detonated large numbers of nuclear weapons in the atmosphere. Nuclear detonations give off enormous amounts of high-energy radiation and, as a result, produce isotopes that aren’t commonly found in the atmosphere, including radioactive isotopes. One of those isotopes is Carbon-14. A small amount of Carbon-14 is made naturally in the atmosphere due to interactions between solar radiation and Nitrogen-14, but in the 1950’s nuclear tests added a much larger pulse of Carbon-14 to the atmosphere. Any organic material made after this date carries the signal of this bomb-generate Carbon-14; everything from your own body to the fabric used in paintings. The Italian scientists took a small corner of this fabric and tested its isotopic composition. Carbon-14 has a half life of over 5000 years, so the pulse of C-14 from the bomb tests would still show up today, only 50 years after the tests. When they tested this painting, supposedly made in 1913, they found the bomb-test carbon present. The painting owned by the Guggenheim is a forgery, made sometime after airborne nuclear tests began. In fact, they estimated the painting was probably made close to 1959, as that is the best match to the isotopic composition of the fabric. Another fascinating use of techniques deployed everyday in the earth sciences. -JBB Image credit: Wikipaintings http://www.wikipaintings.org/en/fernand-leger/contrast-of-forms-1913