Ficheiro:Phanerozoic Climate Change.png

Phanerozoic_Climate_Change.png (726 × 520 píxeis, tamanho: 30 kB, tipo MIME: image/png)

Descrição do ficheiro

Descrição
English:
Expansion showing climate change during the last 65 million years. Note that the scales are not numerically the same since they are based on measurement different types of taxa under different conditions.

This figure shows the long-term evolution of oxygen isotope ratios during the Phanerozoic eon as measured in fossils, reported by Veizer et al. (1999), and updated online in 2004.[1] Such ratios reflect both the local temperature at the site of deposition and global changes associated with the extent of permanent continental glaciation. As such, relative changes in oxygen isotope ratios can be interpreted as rough changes in climate. Quantitative conversion between these data and direct temperature changes is a complicated process subject to many systematic uncertainties, however it is estimated that each 1 part per thousand change in δ18O represents roughly a 1.5-2 °C change in tropical sea surface temperatures (Veizer et al. 2000).

Also shown on this figure are blue bars showing periods when geological criteria (Frakes et al. 1992) indicate cold temperatures and glaciation as reported by Veizer et al. (2000). The Jurassic-Cretaceous period, plotted as a lighter blue bar, was interpreted as a "cool" period on geological grounds, but the configuration of continents at that time appears to have prevented the formation of large scale ice sheets.

All data presented here have been adjusted to 2004 ICS geologic timescale.[2] The "short-term average" was constructed by applying a σ = 3 Myr Gaussian weighted moving average to the original 16,692 reported measurements. The gray bar is the associated 95% statistical uncertainty in the moving average. The "long-term average" is a σ = 15 Myr Gaussian average of the short-term record (see notes).

On geologic time scales, the largest shift in oxygen isotope ratios is due to the slow radiogenic evolution of the mantle. A variety of proposals exist for dealing with this, and are subject to a variety of systematic biases, but the most common approach is simply to suppress long-term trends in the record. This approach was applied in this case by subtracting a quadratic polynomial fit to the short-term averages. As a result, it is not possible to draw any conclusion about very long-term (>200 Myr) changes in temperatures from this data alone. However, it is usually believed that temperatures during the present cold period and during the Cretaceous thermal maximum are not greatly different from cold and hot periods during most of the rest the Phanerozoic. However, recently this has been disputed by Royer et al. (2004), who suggest that the highs and lows in the early part of the Phanerozoic were both significantly warmer than their recent counterparts.

Common symbols for geologic periods are plotted at the top and bottom of the figure for reference.

Long-term evolution

The long-term changes in isotope ratios have been interpreted as a ~140 Myr quasi-periodicity in global climate (Veizer et al. 2000) and some authors (Shaviv and Veizer 2003) have interpreted this periodicity as being driven by the solar system's motions about the galaxy. Encounters with galactic spiral arms can plausibly lead to a factor of 3 increase in cosmic ray flux. Since cosmic rays are the primary source of ionization in the troposphere, these events can plausibly impact global climate. A major limitation of this theory is that existing measurements can only poorly constrain the timing of encounters with the spiral arms.

The more traditional view is that long-term changes in global climate are controlled by geologic forces, and in particular, changes in the configuration of continents as a result of plate tectonics.
Data 12 June 2005
Origem Obra do próprio
Autor Dragons flight
Permissão
(Reutilizar este ficheiro)
This figure was originally prepared by Dragons flight from publicly available data and is part of the Global Warming Art project.
Outras versões
File:Phanerozoic Climate Change.svg é uma versão vetorial deste ficheiro. Ela deve ser usada em vez desta imagem em formato raster, se não for de qualidade inferior.

File:Phanerozoic Climate Change.png → File:Phanerozoic Climate Change.svg

Para mais informações, consulte Ajuda:SVG.

Em outras línguas
Alemannisch  العربية  беларуская (тарашкевіца)  български  বাংলা  català  нохчийн  čeština  dansk  Deutsch  Ελληνικά  English  British English  Esperanto  español  eesti  euskara  فارسی  suomi  français  Frysk  galego  Alemannisch  עברית  hrvatski  magyar  հայերեն  Bahasa Indonesia  Ido  italiano  日本語  ქართული  한국어  lietuvių  македонски  മലയാളം  Bahasa Melayu  norsk bokmål  Plattdüütsch  Nederlands  norsk nynorsk  norsk  occitan  polski  prūsiskan  português  português do Brasil  română  русский  sicilianu  Scots  slovenčina  slovenščina  српски / srpski  svenska  தமிழ்  ไทย  Türkçe  татарча / tatarça  українська  vèneto  Tiếng Việt  中文  中文(中国大陆)  中文(简体)  中文(繁體)  中文(马来西亚)  中文(新加坡)  中文(臺灣)  中文(臺灣)  +/−
Nova imagem SVG

Licenciamento

Image from Global Warming Art
This image is an original work created for Global Warming Art. Please refer to the image description page for more information.
GNU head É concedida permissão para copiar, distribuir e/ou modificar este documento nos termos da Licença de Documentação Livre GNU, versão 1.2 ou qualquer versão posterior publicada pela Free Software Foundation; sem Secções Invariantes, sem textos de Capa e sem textos de Contra-Capa. É incluída uma cópia da licença na secção intitulada GNU Free Documentation License.
w:pt:Creative Commons
atribuição partilha nos termos da mesma licença
A utilização deste ficheiro é regulada nos termos da licença Creative Commons - Atribuição-CompartilhaIgual 3.0 Não Adaptada.
Pode:
  • partilhar – copiar, distribuir e transmitir a obra
  • recombinar – criar obras derivadas
De acordo com as seguintes condições:
  • atribuição – Tem de fazer a devida atribuição da autoria, fornecer uma hiperligação para a licença e indicar se foram feitas alterações. Pode fazê-lo de qualquer forma razoável, mas não de forma a sugerir que o licenciador o apoia ou subscreve o seu uso da obra.
  • partilha nos termos da mesma licença – Se remisturar, transformar ou ampliar o conteúdo, tem de distribuir as suas contribuições com a mesma licença ou uma licença compatível com a original.
Esta marca de licenciamento foi adicionada a este ficheiro durante a atualização da licença GFDL.


References

  • Frakes, L. A., Francis, J. E. & Syktus, J. I. (1992) Climate Modes of the Phanerozoic (Cambridge Univ. Press, Cambridge).
  • Royer, Dana L., Robert A. Berner, Isabel P. Montañez, Neil J. Tabor, and David J. Beerling (2004). GSA Today 14 (3): 4-10. doi:10.1130/1052-5173(2004)014<4:CAAPDO>2.0.CO;2
  • Shaviv, N. and Veizer, J. (2003) Celestial driver of Phanerozoic climate? GSA Today July 2003, 4-10.
  • Veizer, J., Ala, D., Azmy, K., Bruckschen, P., Buhl, D., Bruhn, F., Carden, G.A.F., Diener, A., Ebneth, S., Godderis, Y., Jasper, T., Korte, C., Pawellek, F., Podlaha, O. and Strauss, H. (1999) 87Sr/86Sr, d13C and d18O evolution of Phanerozoic seawater. Chemical Geology 161, 59-88.
  • Veizer, J., Godderis, Y. and Francois, L.M. (2000) Evidence for decoupling of atmospheric CO2 and global climate during the Phanerozoic eon. Nature 408, 698-701.

Notes

  • The statistical errors, plotted in gray, may be significantly smaller than the systematic biases that can occur. Such systematic concerns include:
    1. Different fossil types, spanning different phyla, are measured in different parts of the record, and biological differences in how oxygen is incorporated into different fossils may introduce biases.
    2. Because oxygen isotopes reflect both local temperatures and global glaciation, it is necessary to sample from large spatial areas to provide adequate global coverage. Such extensive coverage may not be available in all time periods (particularly older periods).
  • In constructing the "long-term average", the filter was applied to the short-term averages rather than to the data directly because applying such a filter to the data directly strongly biases the results towards the value at times that have been heavily sampled.


Dragons flight's Temperature Record Series
This figure is part of a series of plots created by Dragons flight to illustrate
changes in Earth's temperature and climate across many different time scales.
Time Period: 25 yrs | 150 yrs | 1 kyr | 2 kyr | 12 kyr | 450 kyr | 5 Myr | 65 Myr | 500 Myr
For articles related to this topic see: Temperature record

Derivative works

Obras derivadas deste ficheiro:  Geologic time scale Climate Change.png

Legendas

Adicione uma explicação de uma linha do que este ficheiro representa

Elementos retratados neste ficheiro

retrata

Histórico do ficheiro

Clique uma data e hora para ver o ficheiro tal como ele se encontrava nessa altura.

Data e horaMiniaturaDimensõesUtilizadorComentário
atual12h57min de 18 de julho de 2010Miniatura da versão das 12h57min de 18 de julho de 2010726 × 520 (30 kB)SeL mediareversed time axis
08h30min de 12 de junho de 2005Miniatura da versão das 08h30min de 12 de junho de 2005726 × 520 (36 kB)Samulili

As seguintes 2 páginas usam este ficheiro:

Utilização global do ficheiro

As seguintes wikis usam este ficheiro:

Ver mais utilizações globais deste ficheiro.

  NODES
Note 4
Project 1