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Telling time is important to scientists who work in the deep past. As humans, we find it difficult to tell time beyond the scale of a lifetime. Last week runs into last month. Those months build up into years and decades. To those of us born in the 1970s, 25 years ago (1990—pre-internet) is half […]

The first comprehensive map of the topsy-turvy climate in the western U.S, 21,000 years ago has been developed by researchers. They focus on when the Southwest was wet and the Northwest was dry, testing it to improve the global climate models that have been developed to predict how precipitation patterns will change in the future.

This blog has been *sleeping* for a few months. Why, you might ask dear reader? Well…the last few months could best be described as schizophrenic. The projects that we’ve been working on are pretty diverse, and they’ve all been progressing, more or less, synchronously. So stay tuned for more details. In the meantime, here’s a rundown of what’s in the hopper.

1. Mammoths and mastodons. Our extinction project is in its last year. The dates are rolling in and we have some very interesting results. We’ve narrowed down the error estimate around the actual time of mastodon extinction to ~250 years. They blip out in the Midwest just as the Younger Dryas, a return to glacial conditions, is getting underway ~12.9 ka. Although mammoths are probably extirpated at about the same time (the last mammoth dates are just a few hundred years earlier than the last mastodon dates), their pattern of extinction is much different. Mastodons go out with a bang. In the last few hundred years prior to extinctions, mastodons are still distributed widely throughout the Midwest. In fact, many sites dating to this time period have multiple animals in them (including Boney Spring, MO, with ~31 mastodons). Mammoths however, are fewer and farther between by the time the terminal Pleistocene rolls around. Although they are here, shoulder to shoulder with mastodons, they are not present in high numbers.

2. MORE Mammoths and Mastodons. Although our project is focused on the extinction of these beasts, we’ve also been able to document quite a bit of morphological diversity in mammoths and mastodons. What do these patterns mean? Are they due to a complex evolutionary history? Or to local environmental pressures? Are there chronoclines (shape and size changes through time) that might give us insight into adaptive strategies?

3. Even MORE Mammoths and Mastodons…and isotopes. We’ve been tweaking our new micromill technique to drill very tiny holes in mammoth teeth. The importance of this research is that it gives us a seasonal-scale picture of the life of a mammoth over the course of a few years. We can see what it was eating and where it was moving (IF it was moving).

4. 3D scanning and printing. In June we received our first 3D printer. In August we received our second. We’ve been working to test the dozens of 3D scans we’ve done over the last year or so. We’re hoping to post them to a gallery soon.

5. Going to the dogs. Illinois is home to one of the most complete records of early dogs in North America. A few years back, we started re-analyzing dog remains from the Koster and Stilwell sites in western Illinois for insight into the lives of these early dogs. I’ll definitely be talking more about them in the next few months.

6. Just batty. Finally, no blog post would be complete without some mention of the bat paleontology that we’ve been working on. Bat guano. Bat bones. Bat ecology.

From mega to micro. Stay tuned for more updates.

C

Precipitation reconstructions are essential for predicting impacts of future climate change and preparing for potential changes in terrestrial environmental conditions. Reliable proxy records of paleoprecipitation, especially from past warm periods, are a valuable tool for assessing and modeling future soil and plant moisture and local water availability. However, current terrestrial proxies are limited in their applications, and as a result, a wide range of paleoenvironments are underrepresented in the geologic record.

Scientists have managed to quantify how the Greenland Ice Sheet reacted to a warm period 8,000-5,000 years ago. Back then temperatures were 2-4 degrees C warmer than they are in the present. Their results are important as we are rapidly closing in on similar temperatures.

Considerable debate surrounds the migration of human populations out of Africa. Two predominant hypotheses concerning the timing contrast in their emphasis on the role of the Arabian interior and its changing climate. In one scenario, human populations expanded rapidly from Africa to southern Asia via the coastlines of Arabia approx. 50,000 to 60,000 years ago. Another model suggests that dispersal into the Arabian interior began much earlier (approx. 75,000 to 130,000 years ago) during multiple phases, when increased rainfall provided sufficient freshwater to support expanding populations.

Recent research has yielded new data on chemical gardens, mysterious formations produced when certain solid salts -- copper sulfate, cobalt chloride -- are added to an aqueous solution of sodium silicate.

Ice and winter floods are important natural disturbances for maintaining species-rich riparian zones along northern watercourses. If the climate becomes warmer this disturbance might be lost. This could potentially lead to a less diverse riparian zone.

A release of carbon dioxide from the deep ocean helped bring an end to the last Ice Age, according to new research. The study shows that carbon stored in an isolated reservoir deep in the Southern Ocean re-connected with the atmosphere, driving a rise in atmospheric CO2 and an increase in global temperatures. The finding gives scientists an insight into how the ocean affects the carbon cycle and climate change.

Sea ice increases in Antarctica do not make up for the accelerated Arctic sea ice loss of the last decades, a new study finds. As a whole, the planet has been shedding sea ice at an average annual rate of 13,500 square miles (35,000 square kilometers) since 1979, the equivalent of losing an area of sea ice larger than the state of Maryland every year.

A massive canyon that is home to Europe's most powerful waterfall was created in a matter of days by extreme flooding, new research reveals.

Researchers have uncovered the earliest evidence of widespread, human-produced air pollution in South America -- from the Spanish conquest of the Inca.

Norway is dotted with small glaciers and permanent snow patches that contain all sorts of archaeological treasures, from ancient shoes to 5000-year-old arrowheads. But climate change has turned up the temperature on these snowfields and they are vanishing at an astonishing rate.

A new study shows that undersea volcanoes flare up on strikingly regular cycles, ranging from two weeks to 100,000 years -- and, that they erupt almost exclusively during the first six months of each year. The pulses -- apparently tied to short- and long-term changes in earth's orbit, and to sea levels -- may help trigger natural climate swings.

Geologists once thought that, until about 18,000 years ago, a mammoth glacier covered the top two-thirds of Ireland. Recently, however, they found evidence that it wasn't just the top two-thirds: The Irish glacier was much larger, completely engulfing the country and extending far offshore.

Natural seepage of methane offshore the Arctic archipelago Svalbard has been occurring periodically for at least 2.7 million years. Major events of methane emissions happened at least twice during this period, according to a new study.

A recent study determined that heavy rainfall events have become more frequent over the last 50 years on Hawai'i Island. For instance, a rare storm with daily precipitation of nearly 12 inches, occurring once every 20 years by 1960, has become a rather common storm event on the Big Island of Hawai'i -- returning every 3-5 years by 2009.

New evidence showing the level of atmospheric carbon dioxide millions of years ago supports recent climate change predictions from the Intergovernmental Panel on Climate Change.

Scientists have found that there is a direct relation between the changes in the earth's orbit and the stability of the Eastern ice cap of Antarctica, more specifically, on the continental fringe of Wilkes Land (East Antarctica).

Earth's crust under Iceland is rebounding as global warming melts the island's great ice caps. In south-central Iceland some sites are moving upward as much as 1.4 inches (35 mm) per year. A new paper is the first to show the current fast uplift of the Icelandic crust is a result of accelerated melting of the island's glaciers and coincides with the onset of warming that began about 30 years ago, the researchers said.