1. Dendrochronology also known as (tree-ring dating) is the scientific method of dating tree rings or growth rings. This methodology is used to determine to find age, location and past events using the trees within the specific regions of the world. They were formed in order to analyze atmospheric conditions during different periods in history. The term Dendros means using trees, chronos means time. The advantages in tree ring dating can identify exact years of tree formation by using the skeleton plot method. Scientists use this plot to graph on paper stips and compare similar patterns in individual trees.
The method is very accurate in finding the age of the tree but also has limitations because of climate. They are then matched with other trees for accuracy. Among the methods Dendrochronology is fundamental in science because it reinforces and expands timelines of ecological events in the past. It is an important dating method because it carries over with carbon dating method and physical anthropology. 2. Dendrochronology came to fruition in 1901 at the the University of Arizona astronomer A. E. Douglass to study trees and timelines of ecological events in the past.
He centered his research around the effects of sunspots on climate. But soon realized that it was a segway in expanding timelines and to better understand current environmental processes and conditions. This allowed scientist to improve understandings of possible future environmental issues. For example early archaeology in the United States began during Thomas Jefferson’s presidency and found skeletons to learn more about mortuary customs.
However they were unsuccessful in determining the actual age of these sites which caused a lot of speculation about their data. Dendrochronology helps scientists understand the specific time frame in which we find these ancient sites. It can also reveal the origin of the wood, understand when and where human activity occurred. Through tree ring dating we are able to find definite climate situations among regions where these sites resided. Trees come in various sizes and so do their rings.
We look at the patterns of rings which can be wide, narrow, jagged or curved. If it rained a lot then the rings would be wider or if during the summer there was a drought then the rings will be narrower. However the rings never repeat patterns. So in looking at these trees by counting the rings. One ring is equal to one year and one hundred rings is equal to one hundred year old tree. Currently there records that date as far back as 11,000 years by taking a younger wood sample with a known date and then comparing it to an older sample, you can determine how much older it is. Once that has been found now it can be used to date and older sample within repetition.
Just as how tree rings grow every year so do scientists knowledge of the past grows with every addition to their findings which can shape our understandings of these timelines and shared ancestry. However dendrochronology is not exclusive in its findings it has compatible techniques to other dating methods. Tree dating is also used for radiocarbon measurements also known as radiocarbon dating. 3. Tree ring dating extends to radiocarbon dating because they are both researching historical records and use the environment to measure data. There are two basic variables with these two dating methods. Dendrochronology measures tree age and climate.
Radiocarbon dating focuses on carbon-14 and organic material such as trees and plants. Carbon 14 is an isotope of the element carbon that is unstable and mildly radioactive. It determines the age of an object that contains organic material by using properties of radiocarbon and these isotopes. Trees are used in radiocarbon dating to calibrate measurements. Scientists will use animals or plants that contain carbon for their research. So most organisms even people produce carbon dioxide through living.
However once they die their bodies decay and stop producing carbon and will enter active decay. Now through the law of radioactive decay scientists are able to find the age. Dendrochronology played an important role in the early days of radiocarbon dating that provided the reference for carbon-14 dating. Nowadays tree rings are used to calibrate these findings. Trees are often used as reference due to its exactness.
But radiocarbon dating has become one of the most significant discoveries in the early 20th century because it has further man’s understanding in the present and past thousands of years. In The Atlas of World Archaeology, Paul Bahn quotes, “Although dendrochronology can provide reliable method of dating, its use is limited to areas where timber was much used and/or where it has been preserved by dry or damp conditions.” In scientific research using more than one dating method is important simply because you want to obtain accurate data. Ring counting does not ensure the accurate dating of each individual ring. Incorrect counting leads to incorrect conclusions drawn from unreliable data. This is why we can can reference to its gold standard called the master chronology. In doing so various techniques are needed to crossdate wood samples to ensure its accuracy as well as carbon dating.
An age can be found by comparing the amount of carbon 14 available in the sample when we use a reference standard like ring counting. It is important to use more than one dating method to find sites or artifacts. If scientists have absolute dates they can compare cultures in different areas and investigate the change in their developments. Dendrochronology is vital to physical anthropology findings because many cultures and civilizations thrived off of natural resources such as trees. Without tree dating it would be hard to exactly find information about specific regions. It is used to create a master chronology of the tree ring patterns to pinpoint particular timelines. Like in the southwest some sites were homes to ancient american indians. Dendrochronology advanced in the precision of dating key events in human timeline.
It’s used in Radiocarbon dating which allows archaeologist to estimate the age of a plant, human and animal remains. Thus allowing anthropologists to accurately study bones and artifacts. A famous example is the 1738 collapse of the Inuit communities in the Alaskan northwest. There were reports of the effect of the Laki volcanic eruption which led to intense winters, famine, and population decrease also known as a bottleneck effect. It became a deserted settlement that had been documents by early European explorers with no comparative data. Only ten survivors from the Kauwerak village were able to orally report the catastrophe.
The tree-ring density measured in the Alaska northwest for 1783 showed the coldest growing season for over 900 years. Using the tree chronology for a region shed light on previously unexplained events, such as sudden migrations of populations, or the emergence of powerful mythologies that influence behaviour and belief systems, as in the Inuit story of Napauruhk and her son.