<p>At that time there were large areas of shallow seas, so small differences in elevation could lead to large differences in water area. I doubt that the elevations are well enough known to estimate the area precisely.</p>
<p><a href="https://dinosaurpictures.org/ancient-earth/#90" rel="nofollow noreferrer">https://dinosaurpictures.org/ancient-earth/#90</a></p>
<p>The coefficient of expansion of water is only <span class="math-container">$207 \times 10^{-6}/K$</span>. 15 degrees would give 0.3%.</p>

CC BY-SA 4.0
2020-09-25T01:28:17.250Z
2020-09-25T01:28:17.250Z
Keith McClary
<p>When the Earth was at its warmest, and there were no ice caps at all, not even during the winter, and thermal expansion meant a certain amount of water took up more space, what ratio of Earth's surface was covered in water?</p>
<p>Also, how much more expansive was water back then? 5% or so?</p>

CC BY-SA 4.0
2020-10-25T02:39:26.933Z
keep in mind geologic effect can drastically change the amount of land covered without any change in sea level. There used to be a seaway through much of middle America that only drained do to tectonic uplift changing the actual height of the land.
John
<climate-change><climate><temperature><paleoclimatology>
How much of the Earth's surface was covered with water during the Mesozoic?
Kurt Hikes
# How much of the Earth's surface was covered with water during the Mesozoic?

(Asked by: username_0 on 2020-09-24)

When the Earth was at its warmest, and there were no ice caps at all, not even during the winter, and thermal expansion meant a certain amount of water took up more space, what ratio of Earth's surface was covered in water?

Also, how much more expansive was water back then? 5% or so?

**Tags:** climate-change, climate, temperature, paleoclimatology

> **Comments:**
> **username_1**: keep in mind geologic effect can drastically change the amount of land covered without any change in sea level. There used to be a seaway through much of middle America that only drained do to tectonic uplift changing the actual height of the land.  

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## 1 answers

### Answer by username_2 on 2020-09-25. Score: 2

At that time there were large areas of shallow seas, so small differences in elevation could lead to large differences in water area. I doubt that the elevations are well enough known to estimate the area precisely.

<https://dinosaurpictures.org/ancient-earth/#90>

The coefficient of expansion of water is only $207 \times 10^{-6}/K$. 15 degrees would give 0.3%.


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