Add dating link russian
The major disadvantage of this method is that one must have a previously age-dated ice core to start with.
In this method one compares certain inclusions in dated ocean cores with related inclusions found in the ice-core of a still undetermined age. Hyde has posted separately some of the relationships between ocean core data and their astronomical causes.
The major disadvantages of this method are that one must compare different signatures of climatic change that correspond to the same event and that one is not certain of the lag times (if any) between oceanic reactions and glacial reactions to the same climatic changes.
After the eruption of volcanoes, the volcanic ash and chemicals are washed out of the atmosphere by precipitation.
This depletion is a temperature dependent process so in winter the precipitation is more enriched in H2(16O) than is the case in the summer.
As the water vapor travels towards the poles it becomes increasingly poorer in H2(18O) since the heavier molecules tend to precipitate out first.
Of the temperature dependent markers the most important is the ratio of 18O to 16O.
A major disadvantage of these types of dating is that they are extremely time consuming.
In these methods, one uses the age of previously determined markers to determine the age of various points in the ice-core.
Both 10Be and 36Cl are formed as charged ions in the ionosphere.
Thus each annual layer starts 10Be and 36Cl poor, becomes 10Be and 36Cl rich, and then becomes poor again. Although what is said above is true, this is an exceedingly minor effect.
9Be and 35Cl) one can determine the season of the year the precipitation occurred.
By comparing the ratios of these isotopes to their nonradioactive counterparts (i.e.