Catastrophism

Source: Wikipedia, the free encyclopedia.
For the idea that Earth-like planets have been affected in the past by short-lived, violent galaxy-wide events, see Neocatastrophism.
The discoveries of different layers of fossils, such as those containing Palaeotherium and Anoplotherium (pictured), by Georges Cuvier led him to believe that series of catastrophic events wiped out worlds before the modern one.

In geology, catastrophism is the theory that the Earth has largely been shaped by sudden, short-lived, violent events, possibly worldwide in scope.[1] This contrasts with uniformitarianism (sometimes called gradualism), according to which slow incremental changes, such as erosion, brought about all the Earth's geological features. The proponents of uniformitarianism held that the present was "the key to the past", and that all geological processes (such as erosion) throughout the past resembled those that can be observed today. Since the 19th-century disputes between catastrophists and uniformitarians, a more inclusive and integrated view of geologic events has developed, in which the scientific consensus accepts that some catastrophic events occurred in the geologic past, but regards these as explicable as extreme examples of natural processes which can occur.

Proponents of catastrophism proposed that each

Noah's flood
.

The French scientist Georges Cuvier (1769–1832) popularised the concept of catastrophism in the early 19th century; he proposed that new life-forms had moved in from other areas after local floods, and avoided religious or metaphysical speculation in his scientific writings.[2][3]

History

Geology and biblical beliefs

Main article: History of geology

In the early development of

Ogygian flood.[4]

Cuvier and the natural theologians

Further information:
Alternatives to Darwinism

The leading scientific proponent of catastrophism in the early nineteenth century was the French

stratigraphic record indicated that there had been several of these revolutions, which he viewed as recurring natural events, amid long intervals of stability during the history of life on Earth. This led him to believe the Earth was several million years old.[5]

By contrast in Britain, where

glaciation theory advocated by Louis Agassiz, following a visit to the Alps where Agassiz demonstrated the effects of glaciation at first hand. As a result of the influence of Jameson, Buckland, and other advocates of natural theology, the nineteenth century debate over catastrophism took on much stronger religious overtones in Britain than elsewhere in Europe.[8]

The rise of uniformitarianism in geology

Uniformitarian explanations for the formation of

geological time, or as the concept came to be known deep time, were found in the writing of James Hutton, sometimes known as the father of geology, in the late 18th century. The geologist Charles Lyell built upon Hutton's ideas during the first half of 19th century and amassed observations in support of the uniformitarian idea that the Earth's features had been shaped by same geological processes that could be observed in the present acting gradually over an immense period of time. Lyell presented his ideas in the influential three volume work, Principles of Geology, published in the 1830s, which challenged theories about geological cataclysms proposed by proponents of catastrophism like Cuvier and Buckland.[9] One of the key differences between catastrophism and uniformitarianism is that uniformitarianism observes the existence of vast timelines, whereas catastrophism does not. Today most geologists combine catastrophist and uniformitarianist standpoints, taking the view that Earth's history is a slow, gradual story punctuated by occasional natural catastrophic events that have affected Earth and its inhabitants.[10]

From around 1850 to 1980, most geologists endorsed

earthquakes, volcanic eruptions, or floods of vastly greater power than those observed at the present time, played any significant role in the formation of the Earth's surface. Instead they believed that the earth had been shaped by the long term action of forces such as volcanism, earthquakes, erosion, and sedimentation, that could still be observed in action today. In part, the geologists' rejection was fostered by their impression that the catastrophists of the early nineteenth century believed that God was directly involved in determining the history of Earth. Some of the theories about Catastrophism in the nineteenth and early twentieth centuries were connected with religion and catastrophic origins were sometimes considered miraculous rather than natural events.[11]

The rise in uniformitarianism made the introduction of a new catastrophe theory very difficult. In 1923

Penrose Medal; the Geological Society of America's highest award.[12]

Immanuel Velikovsky's views

Main article:
Velikovskyism

In the 1950s,

plagues of Egypt, the biblical reference to the "Sun standing still" for a day (Joshua 10:12 & 13, explained by changes in Earth's rotation), and the sinking of Atlantis. Scientists vigorously rejected Velikovsky's conjectures.[13]

Current application

Neocatastrophism is the explanation of sudden extinctions in the palaeontological record by high magnitude, low frequency events (such as asteroid impacts, super-volcanic eruptions, supernova gamma ray bursts, etc.), as opposed to the more prevalent geomorphological thought which emphasises low magnitude, high frequency events.[14]

Luis Alvarez impact event hypothesis

Main article: Cretaceous–Paleogene extinction event

In 1980, Walter and Luis Alvarez published a paper suggesting that a 10 kilometres (6.2 mi) asteroid struck Earth 66 million years ago at the end of the Cretaceous period. The impact wiped out about 70% of all species, including the non-avian dinosaurs, leaving behind the Cretaceous–Paleogene boundary (K–T boundary). In 1990, a 180 kilometres (110 mi) candidate crater marking the impact was identified at Chicxulub in the Yucatán Peninsula of Mexico. These events sparked a wide acceptance of a scientifically based catastrophism with regard to certain events in the distant past.

Since then, the debate about the

mass extinction
events has centered on whether the extinction mechanism was the asteroid impact, widespread volcanism (which occurred about the same time), or some other mechanism or combination. Most of the mechanisms suggested are catastrophic in nature.

The observation of the

Shoemaker-Levy 9
cometary collision with Jupiter illustrated that catastrophic events occur as natural events.

Moon-formation

Main article:
Giant impact theory

Modern theories also suggest that Earth's anomalously large

William K. Hartmann and Donald R. Davis proposed that a catastrophic near-miss by a large planetesimal early in Earth's formation approximately 4.5 billion years ago blew out rocky debris, remelted Earth and formed the Moon, thus explaining the Moon's lesser density and lack of an iron core.[15] The impact theory does have some faults; some computer simulations show the formation of a ring or multiple moons post impact, and elements are not quite the same between the Earth and Moon.[16][17][18]

See also

References

  1. ^ Turney, C.S.M.; Brown, H. (2007). "Catastrophic early Holocene sea level rise, human migration and the Neolithic transition in Europe".
    doi:10.1016/j.quascirev.2007.07.003
    .
  2. ^ a b McGowan 2001, pp. 3–6
  3. ^ a b Rudwick 1972, pp. 133–134
  4. ^ King 1877, p. 450
  5. ^ Rudwick 1972, p. 131
  6. ^ Rudwick 1972, pp. 133–135
  7. ^ Rudwick 1972, p. 135
  8. ^ Rudwick 1972, pp. 136–138
  9. ^ Rudwick 1972, pp. 174–175
  10. ^ "Uniformitarianism". The Columbia Encyclopedia (6th ed.). Columbia University Press. 2007. Archived from the original on 2006-06-24.
  11. ^ Rudwick 1972, pp. 174–179
  12. ^ Penrose Medal 1979 to J Harlen Bretz, Geological Society of America
  13. ^ Krystek, Lee. "Venus in the Corner Pocket: The Controversial Theories of Immanuel Velikovsky". Museum of Unnatural Mystery. Retrieved 2007-12-14.
  14. ^ Goudie, A. Encyclopedia of Geomorphology. p. 709.
  15. S2CID 12983980
    .
  16. ^ "Moonwalk" (PDF). Geological Society of London. September 2009. Retrieved 2010-03-01.
  17. S2CID 122622374
    .
  18. doi:10.1146/annurev.ea.15.050187.001415
    .

Sources

Further reading

External links

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