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The last glacial period of the current ice age ended about 10,000 years ago. [54] Ice melt caused world sea levels to rise about 35 metres (115 ft) in the early part of the Holocene. In addition, many areas above about 40 degrees north latitude had been depressed by the weight of the Pleistocene glaciers and rose as much as 180 metres (591 ft ...
For example, 201.4 ± 0.2 Ma, the lower boundary of the Jurassic Period, is defined as 201,400,000 years old with an uncertainty of 200,000 years. Other SI prefix units commonly used by geologists are Ga (gigaannum, billion years), and ka (kiloannum, thousand years), with the latter often represented in calibrated units ( before present ).
Earth formed in this manner about 4.54 billion years ago (with an uncertainty of 1%) [25] [26] [4] and was largely completed within 10–20 million years. [27] In June 2023, scientists reported evidence that the planet Earth may have formed in just three million years, much faster than the 10−100 million years thought earlier.
The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.
160,000 years ago, Homo sapiens idaltu in the Awash River Valley (near present-day Herto village, Ethiopia) practiced excarnation. [59] 130–80 ka Marine Isotope Stage 5 . Modern human presence in Southern Africa and West Africa. [60] Appearance of mitochondrial haplogroup (mt-haplogroup) L2. 80–50 ka MIS 4, beginning of the Upper Paleolithic.
The table starts counting approximately 10,000 years before present, or around 8,000 BC, during the middle Greenlandian, about 1,700 years after the end of the Younger Dryas and 1,800 years before the 8.2-kiloyear event. From the beginning of the early modern period until the 20th century, world population has been characterized by a rapid growth.
Mars reaches the same solar flux as that of the Earth when it first formed 4.5 billion years ago from today. [99] < 5 billion The Andromeda Galaxy will have fully merged with the Milky Way, forming an elliptical galaxy dubbed "Milkomeda". [102] There is also a small chance of the Solar System being ejected.
About 12.0 ± 3.3 Tmol of O 2 per year today goes to the sinks composed of reduced minerals and gases from volcanoes, metamorphism, percolating seawater and heat vents from the seafloor. [27] On the other hand, 5.7 ± 1.2 Tmol of O 2 per year today oxidizes reduced gases in the atmosphere through photochemical reaction. [ 27 ]