Geologic time scale is a phase of geologic evolutionary history of earth to present.
Explanation:
It's a chronological time scale which shows the dating of rocks, and other events that took place on earth during that period. Primarily divided into eons, from the Haden to Archean to Proterozoic to Phanerozoic. All three are called collectively as Precambrian supereon and eon is divided into eras, period and epochs.
Precambrian starte about 4600 million years ago and ended in 500 million years ago. Based on carbon dating of rocks found 3.8 billion years ago life forms started to emerge, and evidence of plate tectonics motion can be 4280 million ago.
As compared to the phanerozoic era which started from 500 million years ago to present studied as an era of diverse land and aquatic plants and animals. Subdivided as Paleozoic Era, Cambrian Period, Ordovician Period,Silurian Period, Devonian Period, Carboniferous Period and Permian Period.
The original time scale has been altered to fit the scientist dating of rocks and geologic evidence that they have collected and is modified from time to time upon newer discoveries.
La Nina is a combination of oceanic and atmospheric circulation weather pattern that develops into the formation of southern oscillation system of the ENSO cycle and is a comparatively cooler system that its counterpart the El Nino meaning the little boy.
During the period of La Nina, the temperature of the pacific ocean will be normally less than 3 to 5 degrees at least for five months. Thus there are wetter conditions in Indonesia and northern brazil. In North America, this weather phenomenon brings increased rainfall across the upper middle west.
As due to this phenomenon of the La Nina can result in an intense storm in certain places and drought conditions in others as these are associated with synoptic conditions.
Due to La Nina caused catastrophic rainfall in andes it directly impacts the conditions of the Peruvian coasts and hence drought in these areas which sets the conditions of El Nino.
