Looking at Climate
Early work on climate was very long range. Scientists found 500,000 year cycles of climate with subcycles of 100,000 years. Later studies included the interglacial interval at approximately 120,000 years BP, and the last ice age, approximately 18,000 years BP. Many researchers now are interested in 1,500 years cycles in the Holocene, a period of time from the present to approximately 12,000 years ago. We are going to look at work even closer to our own -- a period including the Little Ice Age going back to the 1600's. Those were times of the great plague, changes in agriculture and possibly loss of civilizations. The Icelandic Sagas tell of the Vikings having difficulties travelling between southern Greenland and Iceland, a voyage they had been making for many centuries.
 There is historical documentation of many sitings of icebergs far south from their usual waters. We can determine patterns of cooling and warming climate by looking at the sediment transported by those icebergs. By following the boundaries and tracks of icebergs we know how far ice could travel on ocean currents before they melted. Let's first look at patterns of icebergs dating back to 1890, a time frame that includes when the Titanic had her unfortunate encounter with an iceberg drifting south.
|
