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Radiocarbon c14 dating can be regarded as a dating method for establishing age estimates of organic materials (Bowman, 1990). The radiocarbon technique can say to be one of the most important inventions of the 20th century, especially in the field of human science. This method has led to the entire re-writing of evolution stories and re-thinking of the cultural emergence of human science.
This method has been used in many years to date samples as old as 60,000 years. Willard F. Lebby of the University of Chicago and his colleagues invented this technique immediately after the Second World War (Aitken, 1961). In the current world, this method has offered age determinations in several fields including archeology, geology, and geophysics among others.
The approach utilizes materials sourced from wood, charcoal, marine, and freshwater shells as well as organic bearing sediments. Moreover, carbonate deposits such as coli ache and tufa and dissolved carbon dioxide and carbonates in Oceans, Lakes, and underground water can also offer materials radiocarbon dating age determinations (Stuiver, M.et al, 1998). To this date, radiocarbon dating has found profound applications in archaeological studies and specifically in pre-historic research and studies. More importantly, the radiocarbon dating technique has made significant contributions to hydrology and oceanography. Radiocarbon dating can also be utilized as a geochemical tracer.
Radioactive carbon is generated when nitrogen 14 is bombarded by cosmic rays in the atmosphere (Currie, 2004). After this bombardment, radioactive carbon produced drifts down to the earth where it is absorbed from the air by plants through photosynthesis and food chains (Currie, 2004). It gets into animal bodies when they eat plants and consequently into human bodies when they eat plants and animals.
When a living organism dies, the absorption of C14 stops thereafter radiocarbon C14 that is already in the dead organism starts to disintegrate. Researchers use this fact to determine how much of C14 has disintegrated as well as how much is left in the dead object or item (de Vries, 1958). This is because C14 decays slowly and at a steady rate back to nitrogen 14 (Bowman, 1990). The rate at which C14 decay is known as half-life and carbon 14 has a half-life of 5730 years. This implies that half of the carbon 14 original quantity in the organic matter will have disintegrated within 5730 years. Further, half of the remaining carbon will disintegrate in the next 5730 years and the trend continues like that (Mook et al, 1999).
This means that the determination of the amount of carbon 14 in an object can allow for the discovery of how long the organism has been dead. This is done by establishing the number of beta radiations given out per minute per gram (r/m/g) of a particular object (Mook et al, 1999).
A current C14 unit is approximately that of beta radiations per minute per gram of the object concerned (Stuiver, M.et al, 1998). For carbon 14 which is 5730 years old, it will be only half of that quantity per minute. So, for example, a sample emitting 7.5 radiations per minute in a gram of the object, the organism where the sample material was obtained must be 5730 years old.
The accuracy of the radiocarbon dating method has been tested by the use of an object with an already known date of its death. This has been made possible by the use of historical records, such as some wood taken from Egyptian tombs (Jensen, 2001). Based on the information found on these experiments, it was established that the results were close to those of historical information.
Use of radiocarbon technique in marine geology
Geological features exist within, under, and at the boundaries of oceans, seas, mountains, valleys plains, and so forth in the marine realm in the similar form in which they exist inland (Jensen, 2001). For instance, the earth’s largest continuous mountain chain is the mid-ocean ridge that stretches over 40,000 miles, which rises above the water surfaces in several places such as ice land among others (Jensen, 2001). Further, the Mariana trench which is located in the central Pacific Ocean is deeper than the highest point of the world’s highest mountain that is Mount Everest.
Marine geologists employ sonar and caustic techniques to locate underwater volcanoes. Remote sensing techniques are also used by marine geologists to reap the ridges and valleys. Research and other studies indicate that ocean bottoms are the most active place on earth (Currie, 2004). These findings suggest that in the sea base various activities such as vulcanicity take place almost every day of the calendar and are responsible for the turbulence which is seen daily in oceans and sea as well as other vast water masses.
The formations, composition, and structure as well as the history of the seafloor are the main concern for marine geologists. In this area, geologists examine sediments whereby they tackle the issues of physical features such as size, shape, color, chemical structures as well as weight (de Vries, 1958). They also examine and assess other parameters such as composition and how sediments interact with the environment and other factors including sediment age, origin, distribution, and displacement. Marine geologist combines the knowledge of chemistry and physical oceanography to put together data about how the earth was formed and how the displacement of plates and continents can result to experiences situations such as earthquakes and volcanoes (Jensen, 2001).
Marine geologists use radiocarbon dating to determine historical climate records and animal and plant life by studying sediments and rock core for fossils (Willis, 1996). This is carried out by analyzing and assessing sediment composition among other procedures. Radiocarbon dating is the most significant scientific method marine geologists use to date items. To date a sample from a given material, the amount of radiocarbon present is determined (Willis, 1996). This can be done by measuring the activity of the sample that is the number of beta particles emitted per second. The number of beta particles emitted by the object is directly proportional to the number of radiocarbon atoms (Jensen, 2001). This can be established using several methods. The second method is accelerator mass spectrometry, whereby the device counts the proportion of the number of carbon 14 and carbon 12 atoms in a given sample (Crowe, 1958).
The invention of radiocarbon dating perhaps had a profound influence on modern marine geology than any other technological discoveries. This is particularly true in the prehistoric age whereby without written records, geologists could only speculate on the age of objects (Crowe, 1958). This is to means that before the discovery of the radiocarbon dating technique objects were dated mostly on guesswork and assuming a relationship with other objects. Further, it was impossible to establish dates of many objects before the discovery of the radiocarbon dating technique.
To this date, the radiocarbon dating technique has transformed the nature of marine geology as a field. In the past, marine geologists spent a great deal of time arguing on the age of objects, attempting to formulate chronologies and showing which discoveries predated others (Willis, 1996). They were simply concerned with collecting objects, identifying them, and then dating them. This in effect wasted much of their time thereby limiting the time required for research which as a result led the to development of shallow and unfounded theories. This is because the methods they were using were too inaccurate to warrant any substantive evidence about the age of a particular organism.
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The radiocarbon dating technique allowed chronologies to be determined easily. This as a result as improved the accuracy of age determination. As a result of the radiocarbon dating technique, marine geologists can accurately determine the age of various objects (Stuiver, M.et al, 1998). This in effect as enabled marine geologists to work effectively and efficiently. By use of radiocarbon dating technique, marine can determine with confident age of sediments sandwiched in rocks underwater. These findings are of significant use to the marine geology field in revealing the historical state of a particular phenomenon. The discovery of the radiocarbon dating technique in essence has enabled researchers to spend their time formulating theories about the culture and society of early humans.
Radiocarbon dating techniques are very important to the marine geologist. A marine geologist uses this technique to date organic matter in marines such as rock and sediments deposited by glaciers (Mook et al, 1999). Moreover, this technique provides an invaluable tool to many researchers in determining the age of plant or animal matter. For instance, the recent application of this technique on tusks found frozen in the arctic ice on a remote island were discovered to be 4000 years old (Jensen, 2001). This is a good example to illustrate how the radiocarbon dating technique is insightful.
The radiocarbon dating technique is widely used by earth science researchers in hydrology, oceanography, climatology, and environmental science. In marine geology, deep-sea sediments can be dated from calcite shells as well groundwater from dissolved carbonate (Stuiver, M.et al, 1998). Further, carbon dioxide trapped in ice cores can be dated offering atmosphere samples for various ages.
This technique also has other obvious utilizations. Studies are being carried out to establish if there are any clues for past intense cosmic ray activity in radiocarbon levels (Currie, 2004). This in effect can offer humanity a record of the past supernova as well as astronomical phenomena. Radiocarbon dating technique can also be employed as a biomedical tracer since many biochemical contains carbon (Currie, 2004). This in essence can be of significant value to humanity and particularly in human medicine development.
This technique offers a reliable approach for dating objects in the range of 300 – 30,000 years old (Willis, 1996). The technique is not 100% accurate as samples can be contaminated by calcium carbonate from groundwater as well as humic acids from organic matter in the soil. Research and other studies point out that the marine sample indicates a lower level of radiocarbon (Jensen, 2001). This is because some of the radiocarbons normally disintegrate by the time it dissolves in the sea.
The level of radiocarbon in the biosphere is not constant and therefore it very essential to calibrate radiocarbon data to generate accurate results (Currie, 2004). This is accomplished by comparing the dendrochronology commonly known as tree ring and radiocarbon dates of wood samples obtained from the bristlecone price tree which is known to live for nearly more than 4000 years (Currie, 2004). Because there is no carbon transfer between the rings, the radiocarbon content of the center of the tree is less than the younger wood on the outside. This in effect allows the technique to act as a corrective for different content.
To this date, the major developments in the radiocarbon technique are concerned with the improvement in measurement techniques. Currently, studies and research are being carried out to develop effective and efficient measurement techniques. This is an effort to develop more versatile measurement techniques capable of dating various materials. This because the initial radiocarbon method is limited in the material of which it can measure accurately. The initial radiocarbon technique developed by Willard F. and a team of scholars from the University of Chicago was the primary centered solid carbon technique.
Although currently there are procedures that can be used to date solids, there is a need to developed more advanced techniques capable of dating a variety of objects including solids and liquid among others. This in essence can help marine geologists in their work which involves dealing with things underwater. Further, marine geologists should look for ways of combining the radiocarbon technique with other techniques. This in effect increases their accuracy when dating objects sourced underwater. The radiocarbon dating technique is a very important tool in marine geology as it facilitates the determination of the age at which a particular organism existed.
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