There’s a new article at Nature News where they report on an amazing new paleoclimatology breakthrough with temperature reconstructions using clamshells. The Nature article reports on a new paper in PNAS from William Patterson at the University of Saskachewan. Here’s a short excerpt:
The study used 26 shells obtained from sediment cores taken from an Icelandic bay. Because clams typically live from two to nine years, isotope ratios in each of these shells provided a two-to-nine-year window onto the environmental conditions in which they lived.
Patterson’s team used a robotic sampling device to shave thin slices from each layer of the shells’ growth bands. These were then fed into a mass spectrometer, which measured the isotopes in each layer. From those, the scientists could calculate the conditions under which each layer formed.
Unlike counting tree rings which have varying widths due to all sorts of external influences such as rainfall, sunlight, temperatures, available nutrients, and available CO2, this method looks at the levels of different oxygen isotopes in their shells that vary with the temperature of the water in which they live. One simple linear relationship.
The data resolution from isotope counts is incredible.
“What we’re getting to here is palaeoweather,” Patterson says. “We can reconstruct temperatures on a sub-weekly resolution, using these techniques. For larger clams we could do daily.”
The reconstruction is shown below. We see familiar features the little ice age, the medieval warm period and the downturn which led to the extinction of Norse settlements on Greenland.
And the feature of this reconstruction to surely stick in the craw of many who think we are living in unprecedented times of warmth is the “Roman Warm Period”. Have a look:
From Nature: Shellfish could supplant tree-ring climate data
Temperature records gleaned from clamshells reveal accuracy of Norse sagas.
Richard A. Lovett
Oxygen isotopes in clamshells may provide the most detailed record yet of global climate change, according to a team of scientists who studied a haul of ancient Icelandic molluscs.
Most measures of palaeoclimate provide data on only average annual temperatures, says William Patterson, an isotope chemist at the University of Saskatchewan in Saskatoon, Canada, and lead author of the study1. But molluscs grow continually, and the levels of different oxygen isotopes in their shells vary with the temperature of the water in which they live. The colder the water, the higher the proportion of the heavy oxygen isotope, oxygen-18.
The study used 26 shells obtained from sediment cores taken from an Icelandic bay. Because clams typically live from two to nine years, isotope ratios in each of these shells provided a two-to-nine-year window onto the environmental conditions in which they lived.
Patterson’s team used a robotic sampling device to shave thin slices from each layer of the shells’ growth bands. These were then fed into a mass spectrometer, which measured the isotopes in each layer. From those, the scientists could calculate the conditions under which each layer formed.
“What we’re getting to here is palaeoweather,” Patterson says. “We can reconstruct temperatures on a sub-weekly resolution, using these techniques. For larger clams we could do daily.”
It’s an important step in palaeoclimatic studies, he says, because it allows scientists to determine not only changes in average annual temperatures, but also how these changes affected individual summers and winters.
“We often make the mistake of saying that mean annual temperature is higher or lower at some period of time,” Patterson says. “But that is relatively meaningless in terms of the changes in seasonality.”
For example, in early Norse Iceland — part of the 2,000-year era spanned by the study — farmers were dependent on dairy farming and agriculture. “For a dairy culture, summer is by far the most important,” he says. “A one-degree decrease in summer temperatures in Iceland results in a 15% decrease in agricultural yield. If that happens two years in a row, your family’s wiped out.”
Technically, the molluscs record water temperatures, not air temperatures. But the two are closely linked — specially close to the shore, where most people lived. “So, when the water temperatures are up, air temperatures are up. When water temperatures are down, air temperatures are down,” Patterson says.
Read the complete article at Nature News
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Kelyfoclimatology?
I will never see a raw clam (only way to eat ’em) in the same light, as it gets washed down my gullet with a cold brew. I will send a prayer of thanks for each little morsel. On a serious note, this is absolutely brilliant! Who knew?????
mmmmmmm…slurp slurp….mmmmmmmmmmmm
The graph is missing ….
[Reply: until it’s fixed, just click on the blank box and the embiggened chart will appear. ~dbs, mod.]
Someone just needs to graft the instrumental record on the tail end of that puppy, and the clams can play hockey, too!
Sorry sir, but this, sounds too much like science. I believe computer models, scientific papers where the raw data is unavailable and conspiracy of big oil is more logical.
Mann puts it perfectly. “The side that is issuing these attacks, our detractors, are extremely well-funded, they are extremely well-organized. They have basically had an attack infrastructure of this sort for decades. They developed it during the tobacco wars. They honed it further in efforts to attack science that industry or other special interests find inconvenient. So they have a very well-honed, well-funded, organized machine they are bringing to bear now in their attack on climate science.”
Forget about the science, forget about my emails, let me tell you a story of big greasy oil, sending professional squad teams against good scientists like me. Be afraid, woOoohhh.
I don’t get a reconstruction image on screen, for some reason.
[Reply: click on the blank box, you’ll get it. ~dbs, mod.]
“If he can find the funding, that is exactly what Patterson would like to establish next. “We have what may be the world’s oldest clam,” he says, “that might give a continuous record going back 400 years.””
So, we have a “demonstration” that covers the period up to 1650 and if Patterson gets the funding we will get the clam record of the past 360 years!
It looks promising, mabe this is money well spend!
“So, when the water temperatures are up, air temperatures are up. When water temperatures are down, air temperatures are down,” Patterson says.
Dunno. Ever swim in a ocean inlet or bay? The surface water down to about three feet is nice and toasty. Get below that, where there are plenty of bivalves, and water temps drop rapidly.
I’m with Pamela, prefer eating on half shell than reading paleoclamate.
The image doesn’t seem to show.
[Clicky in box, image appear. ~dbs, mod.]
“The study used 26 shells obtained from sediment cores taken from an Icelandic bay. Because clams typically live from two to nine years, isotope ratios in each of these shells provided a two-to-nine-year window onto the environmental conditions in which they lived.”
So they are after a 2,000 year timespan of sedimentary layers to examine oxygen isotopes in clamshells. This will yield temperatures in a sub-weekly resolution. That is placing a lot of confidence in the accuracy of the dating of the stratigraphy in the cores. That is putting all your clams in one basket!
I foresee an undending series of Clam jokes coupled with Climate science. “Climate scientists clam up on Warm periods’. Seriously, given the ability to both carbon date any remaing organic matter in a clamshell and analyse the corresponding water temperature makes dendrochronology a dead end for climate reconstruction. There are the limitations that it can only give the shallow water temperatures but that never stopped the dendro’s.
This theory is way wrong. The water temps vary in different spots that are not far apart.
Let’s turn loose about 6 teams and see if their results are identical.
“For a dairy culture, summer is by far the most important,” he says. “A one-degree decrease in summer temperatures in Iceland results in a 15% decrease in agricultural yield. If that happens two years in a row, your family’s wiped out.”
I will take the one degree increase in summer temperatures over an increase in energy and food costs through carbon rationing, any day!
“Decrease,” that is. Or increase!
[Clicky in box, image appear. ~dbs, mod.]
Nothing happens.
[I get it with no problem. But I’ll look into it ASAP. In the mean time, you can get the same image from the link in the last sentence of the article. ~dbs]
Error bars! What are these . . . error bars?!
Clamy…how I love ya…how I love ya…my dear ol’ Clamy!”
…and so the Mann says to the clam, “Have you heard the one about the hockey stick…..”
This will fill in the gaps in the SH record regarding the MWP. Researchers down under should jump on this. Lots of data is needed to build confidence, so nothing will be wasted. Australia (both ends), NZ, Chile, S. Africa, etc. should each fund a couple of studies.
If you want the graph, click on the link to the article itself, then click on the thumbnail image within the article.
I tried clicking in the box but nothing happens.
REPLY: Yes the pinheads at Nature don’t allow image sharing links. I’ve fixed their problem. -A
PS: A miracle has happened.
Use this link to the image in the above text:
http://www.nature.com/news/2010/100308/images/800px.chart.2010.Fig3_mussels.jpg
Geoducks have a lifespan up to 150 years.
Nothing could be finer than to spend a Sunday morning at the Acme Oyster House in New Orleans, slurping down oysters and drinking a bloody Mary!
Looks like the video is correct,
Unstoppable Solar Cycles (Video) (10min)