An extract on #toprankrepost
The geological record appears to show that ice ages start when the continents are in positions which block or reduce the flow of warm water from the equator to the poles and thus allow ice sheets to form. The ice sheets increase Earth's reflectivity and thus reduce the absorption of solar radiation. With less radiation absorbed the atmosphere cools; the cooling allows the ice sheets to grow, which further increases reflectivity in a positive feedback loop. The ice age continues until the reduction in weathering causes an increase in the greenhouse effect.
There are three known configurations of the continents which block or reduce the flow of warm water from the equator to the poles:
A continent sits on top of a pole, as Antarctica does today.
A polar sea is almost land-locked, as the Arctic Ocean is today.
A supercontinent covers most of the equator, as Rodinia did during the Cryogenian period.
Since today's Earth has a continent over the South Pole and an almost land-locked ocean over the North Pole, geologists believe that Earth will continue to experience glacial periods in the geologically near future.
Some scientists believe that the Himalayas are a major factor in the current ice age, because these mountains have increased Earth's total rainfall and therefore the rate at which carbon dioxide is washed out of the atmosphere, decreasing the greenhouse effect. The Himalayas' formation started about 70 million years ago when the Indo-Australian Plate collided with the Eurasian Plate, and the Himalayas are still rising by about 5 mm per year because the Indo-Australian plate is still moving at 67 mm/year. The history of the Himalayas broadly fits the long-term decrease in Earth's average temperature since the mid-Eocene, 40 million years ago.
In addition, it (along with the IATA) is the body responsible for the standard international codes for airlines, airports, hotels, cities and car rental firms (for example, the three-digit codes that designate London Heathrow Airport as LHR). These codes provide a method to link international travel network with international suppliers.
Until the 21st Century and the European Union's market abuse laws, the United States was the leading country in prohibiting insider trading made on the basis of material non-public information. Thomas Newkirk and Melissa Robertson of the U.S. Securities and Exchange Commission (SEC) summarize the development of US insider trading laws. Insider trading has a base offense level of 8, which puts it in Zone A under the U.S. Sentencing Guidelines. This means that first-time offenders are eligible to receive probation rather than incarceration.