Continental drift and climate

E. Linacre & B. Geerts

1/'02

Movements of the Earth’s tectonic plates have altered the world’s geography, as shown in Fig A. This in turn changed the temperatures of particular places (1, 2). The waters around New Zealand's south island, for instance, cooled from 20° C at the beginning of the Eocene about 53 million years ago, to about 17° C during 30-14 Ma BP, then cooling to the present 12° C (3). This is partly because of net poleward movement, partly because of Antarctic cooling (a permanent ice sheet formed about 5 Ma BP), and partly because of changing ocean currents (a warm current similar to the Gulf Stream affected the east coast of Australia-Antarctica in the Eocene).

Fig 1. (right) Continental movement during the past 225 million years (3).

(top) The world during the Late Cretaceous (94 M years BP).

The arrows indicate the direction of the continental drift.

References

(1) Williams, M.A.J., D.L. Dunkerley et al. 1993. Quaternary Environments (Edward Arnold) 329pp.

(2) Frakes, L.A. 1979. Climates Throughout Geologic Time (Elsevier) 310pp.

(3) Sturman, A. and N. Tapper 1996. The Weather and Climate of Australia and New Zealand (Oxford Univ Press) 476pp.