links for 2009-06-30

links for 2009-01-12

  • “A team of scientists exploring Springs Preserve with remote-sensing gear [Ground Penetrating Radar –ed.] has found what appears to be a prehistoric village of pit houses where as many as 30 Anasazi people lived about 1,300 years ago, the preserve’s archaeologist said Friday.” This is the full version of the ‘breaking news’ version I just posted.
    This is the project I was the archaeologist for from 2000 – 2005. We dug the pit house that yielded the radiocarbon dates.
  • "A team of scientists exploring Springs Preserve with remote-sensing gear have found what is believed to be a prehistoric village of pit houses where as many as 30 Anasazi lived about 1,300 years ago, the preserve's archaeologist said Friday."
    I was the archaeologist at the Springs from 2000 – 2005. We dug the partially excavated pit house they reference in 2003.

links for 2009-01-10

  • "Leon Panetta was in the small handful of people who knew there was a terrorism problem long before anybody else had heard of al-Qaeda." — Richard A. Clarke [you’ve heard of him, right?]
    (tags: obama Panetta CIA)
  • "The Republicans' sudden reversion to the solemn frugality of their forebears would be amusing were it not so dangerous. Having established a record over the past decade or so as the wildest wastrels in the nation's history, they now present themselves as straight-laced accountants who simply cannot abide a misspent dime."
  • A pair of strong solar storms that hit Earth late last week were squalls compared to the torrent of electrons that rained down in the "perfect space storm" of 1859. And sooner or later, experts warn, the Sun will again conspire again send earthlings a truly destructive bout of space weather.(…)
    The event 144 years ago was three times more powerful than the strongest space storm in modern memory, one that cut power to an entire Canadian province in 1989. A new account of the 1859 event, from research led by Bruce Tsurutani of NASA's Jet Propulsion Laboratory, details the most powerful onslaught of solar energy in recorded history. [via Doug]
  • Historical records tell us that from the beginning of March 536 AD, a fog of dust blanketed the atmosphere for 18 months. During this time, "the sun gave no more light than the moon", global temperatures plummeted and crops failed, says Dallas Abbott of Columbia University's Lamont-Doherty Earth Observatory in New York. The cause has long been unknown, but theories have included a vast volcanic eruption or an impact from space.
    Now Abbott and her team have found the first direct evidence that multiple impacts caused the haze. They found tiny balls of condensed rock vapour or "spherules" in debris inside Greenland ice cores dating back to early 536 AD. Though the spherules' chemistry suggests they did not belong to an impactor, they do point to terrestrial debris ejected into the atmosphere by an impact event, Abbott says. "This is the first concrete geological evidence for an impact at 536 AD." [via Doug Miller]

links for 2008-12-19

Danish Arctic Research Dates End of Ice Age to 11,711 Years Ago

Well cool! Urm, pun not intended. Archaeologists seldom need quite that precision, but just to know that we’re closer to 12KYA than 11 is useful. Now on to that whole “Younger Dryas” event.

Danish Arctic research dates Ice Age

The result of a Danish ice drilling project has become the international standard for the termination of the last glacial period. It ended precisely 11,711 years ago.

Jørgen Peder Steffensen of the Niels Bohr Institute showing the exact point in the ice cap where the last Ice Age ended – 11,711 years ago. – Foto: Niels Bohr Instituttet

A Danish ice drilling project has conclusively ended the discussion on the exact date of the end of the last ice age.

The extensive scientific study shows that it was precisely 11,711 years ago – and not the indeterminate figure of ‘some’ 11,000 years ago – that the ice withdrew, allowing humans and animals free reign.

According to the Niels Bohr Institute (NBI) in Copenhagen, the very precise dating of the end of the last Ice Age has made Denmark the owner of the “Greenwich Mean Time” of the end of the last glacial period and beginning of the present climate – the so-called International Standard Reference.

Kilometres of ice
It took several thousand years to warm up the earth and melt the kilometre thick ice caps that covered large parts of the northern hemisphere during the last glacial period and as a result the transition from Ice Age to the current period has lacked a clearly defined point in time.

The answer has now been found in the NordGrip drilling project in Greenland.

“Our new, extremely detailed data from the examination of the ice cores shows that in the transition from the ice age to our current warm, interglacial period the climate shift is so sudden that it is as if a button was pressed”, explains ice core researcher Jørgen Peder Steffensen, Centre for Ice and Climate at NBI at the University of Copenhagen.

Ice core reference
When ice cores, that are formed by annual snowfall that is compressed into ice, are drilled out and analysed, the three kilometre ice cap in Greenland has acted like a filing cabinet of the climate detail of past geological periods.

“It is the first time an ice core has been used as an international standard reference for a geological period and it is a great recognition of our extremely detailed scientific data”, Jørgen Peder Steffensen said.

6,011 Years Ago*

Today it is also worth noting that the first day of creation began at nightfall preceding Sunday October 23, 4004 B.C. The anniversary of which would be nightfall yesterday. Or something like that.

* [(4004 + 2008) -1 = 5,999 6,011 Remember, there’s no year zero.] later: WTF’s wrong with my math skills? Sheesh.

Happy Mole Day!

Via Mic Check Radio:

Happy Mole Day!
The mole is the International System of Units base unit of measurement for the amount of substance, “usually limited to measurement of subatomic, atomic, and molecular structures.” One mole contains Avogadro’s number, which is approximately 6.0229×1023. So this morning the date read 6:02am 10/23, get it?