An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers for shallow holes or powered drills; they can reach depths of over two miles 3. The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core. The proportions of different oxygen and hydrogen isotopes provide information about ancient temperatures , and the air trapped in tiny bubbles can be analysed to determine the level of atmospheric gases such as carbon dioxide.
In fact, there are good reasons to believe that the ice cores are revealing important information about conditions following the Flood of Genesis and the recent formation of thick ice sheets. Reports of ice-core data containing records of climatic changes as far back asyears in the past are dependent upon interpretations of these data which could be seriously wrong, if the Genesis Flood occurred as described in the Bible.
Further research on ice-core data should be a high priority for creationist researchers. Barnola, J. Raynaud, Y. Korotkevich, and C. Lorius, Bloomberg, R. Epstein, S. Sharp, and A. Gow, Hammer, C. Clausen, W. Dansgaard, N. Gundestrup, S. Johnsen, and N. Reeh, Clausen, and W. Dansgaard, Johnsen, S. Dansgeard, and H.
Clausen, Jouzel, J.
Merlivat, Jonzel, J. Lorius, J. Petit, C. Genthon, N.
Barkov, M. Kotlyakov, and M. Petrov, Lorius, C.
How are ice cores dated?
Merlivat, J. Jonzel, and M. Pourchet, Jouzel, C. Ritz, L.
Introduction It is not uncommon to read that ice cores from the polar regions contain records of climatic change from the distant past. Research teams from the United States, the Soviet Union, Denmark, and France have bored holes over a mile deep into the ice near the poles and removed samples for analysis in their laboratories. Aug 16, Record Shattering Million-Year-Old Ice Core Reveals The Genesis Of Ice Ages use ice cores dating back millions of years to determine the climate of the time, let's walk through the steps Author: Trevor Nace.
Merlivat, N. Barkov, Y.
Korotkevich, and V. Kotlyakov, Oard, M. Cite this article: Larry Vardiman, Ph.
Ice Cores and the Age of the Earth. Skip to main content. More Features. The Latest. A new study published in the Proceedings of the National Academy of Sciences has again tried to explain a global erosional surface known as the Great Unconformity. Common shrews are uniquely engineered creatures that have a high metabolism-very different from your average mammal. And now biologists have just People will often ask, "Why would a good and perfect God allow bad things to happen?
Then they can know the story told for an exact year. It is like counting the rings on a tree, but it is actually much more accurate.
It also tells a much larger story than a tree or forest possibly could. Since Greenland is near the end of the path for the Gulf Stream and most of the water vapor in the atmosphere in that region is from the Gulf Stream, ice cores from Greenland are a good indicator of the ocean temperatures in the north Atlantic Ocean.
Ice cores in Alaska tell the story of the north Pacific Ocean. Different regions of Antarctica tell different stories based on the weather patterns of that region.
The simplest reason that it works this way is that cold water does not evaporate very much. Since there is much more light oxygen than heavy oxygen, cold water evaporates very little heavy oxygen. The warmer the water, the more heavy oxygen is released.
So ice cores are really telling a larger story than they are often given credit for. That is why they are so useful in understanding the global climate. A coral reef can tell a story, but only at the exact location that the coral exists. This is especially true for the past couple of million years as most of the climate changes have been far stronger in the Northern Hemisphere than they have in any other place on Earth. There are very few corals in that part of the world.
This is also why ice cores in Antarctica can measure changes that are mostly happening in the Northern Hemisphere. Temperatures in Antarctica do not change as much as the ice cores indicate. What does change is how much warm water is close to Antarctica. During a glacial period ice age the oceans near both poles are much colder so the amount of heavy oxygen is very small. When the the northern hemisphere is warmer like now the oceans have a higher sea level and warmer water is closer to the both poles.
Even if a location in Antarctica stayed exactly the same temperature foryears, the ice core at that location would tell the temperature record of the ocean that evaporated the water that fell as snow at that location. In this way ice cores do not reflect the temperature of the location they are drilled. Ice cores primarily tell the record of the ocean the snow evaporated from and how far that water vapor traveled.
Any type of record that involves the ratio of oxygen that has fallen as rain can also tell the same story. Water that drips in caves to form stalagmites and stalactites can also be used to determine information like this. In places where there are no glaciers this type of thing can be done, but it is more complicated.
Ice cores give the broadest temperature reconstruction because of how the record accumulates. Each layer is distinct and can provide a wide view of the climate for the region for that specific year.
This information is recorded for the period that matches the age of the glacier. The bottom and older layers do get squeezed by the weight above, but reliable ice cores that are hundreds of thousands of year old have been recovered.
The specific oxygen isotopes are 16 O and 18 O.
The hydrogen isotopes are hydrogen and deuterium. These are often called the stable isotopes. They are used precisely for the reason that they are stable over time. There can also be combinations of the the different isotopes in a water molecule.
Ice core dating accuracy
The heavier the overall molecule is, the less it will evaporate and the quicker it will condense. Anything that triggers condensation will drop the amount of 18 O that is present. Altitude is another factor that makes a difference as it also decreases the 18 O content of the ice.
What this does is complicate the comparison of ice cores. One location will have a different general path that the water molecules take. An ice core from a lower location will generally have a higher ratio of 18 O. This makes comparing ice cores difficult. Each one must be separately calibrated to temperature. For this reason ice core data is not often converted to temperature, but left as isotope ratios.
So scale is a factor that can be ignored or calibrated. Precise scale calibration is usually not needed though as the relative changes are sufficient. This is also why different ice cores have different ranges in the isotope record.
The farther they are from the ocean source, the less the range will be. Some of the Greenland ice cores have a very large range as the Gulf Stream can get warm water close to Greenland. The Taylor ice core from Antarctica has about half the oxygen isotope range that those in Greenland do. That makes the oxygen isotopes less useful in those locations.
The light oxygen with the deuterium can make it that far though and those ratios can be used instead of oxygen. This should make it clear that ice cores do not tell the local temperature.
There is no mechanism for the temperature of a location on an ice sheet to dictate the stable isotope ratios in the snow that falls there. It is truly a function of the distance and path from the location of evaporation to the location that the water molecules became part of the ice sheet. No single type of record carries as much of a global temperature signal as the ice cores do.
That is why they are so often used in paleoclimatology. A single ice core reveals a broader picture than any other method. The main limiting factor for ice cores is of course location. They only exist where there is permanent ice sheets.
Overview (Scientific Content below) There have been a variety of discussions in the past week about what ice core data tells us. There are several misconceptions about what information the ice core data contains. Some people believe that it is the air bubbles trapped in the ice that tell the temperature history of the Earth and others be. How are samples acquired without destroying the ice? I imagine keeping the ice intact as much as possible would be extremely valuable. Some of the answers to these questions are available on the Ice Core Basics page. Ice cores can be dated using counting of annual layers in their uppermost layers. Dating the ice becomes harder with depth. Jun 27, Ice samples pulled from nearly a mile below the surface of Greenland glaciers have long served as a historical thermometer, adding temperature data to studies of the local conditions up to the Northern Hemisphere's climate. But the method - comparing the ratio of oxygen isotopes buried as snow fell over millennia - may not be such a straightforward .
Glaciers that have a flow are also useless as the record from a core is not a time series. That is why only certain glaciers or parts of glaciers can be cored. Another problem is glaciers on locations that have warm rock ie on a volcano. The bottom of the glacier is often melting and the age of the glacier is difficult to determine.
That makes the temperature of the bottom ice of a core important. Cold ice at the bottom is an indication that the bottom ice was the forming layer of the glacier.
That information can also be very, very useful. Main Source. Scientific content is better when backed by journal references. Some of what you say is in considerable variance to say Jouzel et al or say Alley Furthermore you use that interpretation to push the claim that temperatures for most of the holocene were warming than now which can hardly be supported by evidence of say arctic ice extent, glacial retreat levels etc, never mind other proxies.
The NH does indeed appear to have been warmer for the most of the holocene based on evidence presented in WG1. However, I stand by published science that I see in saying that isotopes largely reflect the temperature of the site where precipitation occurs. I am aware of the calibration issues associated with ocean wide changes in water sources though.
ice cores (Oeschger, ; Wolff, ; with a third planned for the International Partnerships in Ice-Core Science meeting). Here, after brief mention of some general ice-core history, I will highlight a few of the many reasons why ice-core results are so highly reliable through review of some of the historically keyadvances. To demonstrate the methods used in dating ice-cores I will use the Vostok ice-core as an example because I found plenty of literature on it and because it is an Antarctic ice-core which was what the original post was about. How It Was Collected The Vostok Ice-Core was collected in East Antarctica by the Russian Antarctic expedition. Ice Core Dating. By sampling at very fine intervals down the ice core, and provided that each annual layer of snow is thick enough, several samples from each year may be measured for the different chemical properties. It has already been seen that the delta value is related to air temperature when the snow was deposited.
I appreciate your willingness to accept the the early Holocene was warmer than we are today. That is something that not many people with your view very willingly accept.
There is complexity in the path of the water vapor to the location, but the distance the water vapor travels is very important to the heavy oxygen isotope. The way I stated it is unusual, but my purpose is to help people understand. I indeed succeeded with this article.
The article I used as a source does have several journal references. Here they are. I did link the source at the bottom of the article.
Benefits of Ice Core Dating
Bradley, R. Cole, J. Dunbar, T. McClanahan, and N. Tropical Pacific forcing of decadal variability in the western Indian Ocean over the past two centuries, Science Jouzel, J. Koster, R.
Explaining the science of Antarctic glaciers
Suozzo, G. Stable water isotope behavior during the last glacial maximum: A general circulation model analysis. Journal of Geophysical Research, In the northern hemisphere, much of the holocene was warmer. Down here is different as you see in the WG1 synthesis.