Fandom

Global Warming Wikia

Phanerozoic Sea Level.png

83pages on
this wiki
Add New Page
Talk0
Phanerozoic_Sea_Level.png (download)‎ (523 × 360 pixels, file size: 19 KB, MIME type: image/png)

Summary Edit

This figure compares the Hallam et al. (1983) and Exxon eustatic (global) sea level reconstructions for the Phanerozoic eon. The Exxon curve [1] is a composite from several reconstructions published by the Exxon corporation (Haq et al. 1987, Ross & Ross 1987, Ross & Ross 1988). Both curves are adjusted to the 2004 ICS geologic timescale.

Hallam et al. and Exxon use very different techniques to measuring global sea level changes. Hallam's approach is qualitative and relies on regional scale observations from exposed geologic sections and estimates of the areas of flooded continental interiors. Exxon's approach relies on the interpretation of seismic profiles to determine the extent of coastal onlap in subsequently buried sedimentary basins. Hallam is insensitive to rapid fluctuations in sea level. Exxon is sensitive to rapid fluctuations but tends to overinterpret local geologic changes resulting in bias towards reporting unphysical rapid fluctuations.

The depth scale is as reported by Exxon. Because Hallam is reported as qualtitative (i.e. uncalibrated), these sea level changes were scaled to match the Exxon record during the period 0-250 Myr.

A black bar is added to indicate the scale of sea level fluctuations during the last glacial/interglacial transition. This change occurred purely within the last 20 kyrs, and note that neither system of measurements is capable of resolving changes on this time scale. It also should be noted that very rapid fluctuations of similar scale are potentially possible during all periods during which large scale ice sheets are present (see: Phanerozoic climate change).

On the scale of this figure, the melting of all existing ice sheets would result in a sea level rise of ~80 meters. Changes on larger scales, which evidently occurred many times in the past, are the result of geologic changes in the structure of ocean basins. Essentially, such changes affect the average depth of the oceans relative to the continents.

Common symbols for geologic periods appear at the bottom.

Licensing Edit

This file is licensed under the GFDL. Permission is granted to copy, distribute and/or modify this image under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. Subject to Wikia disclaimers.


Appears on these pages
of

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current17:17, April 21, 2007Thumbnail for version as of 17:17, April 21, 2007523 × 360 (19 KB)Eric Wester (Talk | contribs)This figure compares the Hallam et al. (1983) and Exxon eustatic (global) sea level reconstructions for the Phanerozoic eon. The Exxon curve [1] is a composite from several reconstructions published by the Exxon corporation (Haq et al. 1987, Ross & Ross 1

Ad blocker interference detected!


Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.