<p>over that short a time there would be very little change in the land itself, all you really get is a sea level change due to changes in the ice sheets, continental movement is barely noticeable.</p>
<p>such <a href="https://en.wikipedia.org/wiki/Past_sea_level" rel="nofollow noreferrer">measurements</a> and <a href="https://www.reddit.com/r/MapPorn/comments/6jm21e/global_coastlines_precatastrophic_sea_level_rise/" rel="nofollow noreferrer">maps</a> already exist.</p>
<p>here is the earth 12,000 years ago.
<a href="https://i.sstatic.net/aIRPI.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/aIRPI.jpg" alt="enter image description here" /></a></p>
<p>Here is the same map with the changes highlighted.
<a href="https://i.sstatic.net/0SxZr.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/0SxZr.jpg" alt="enter image description here" /></a></p>
<p>sources for other maps
<a href="https://www.fieldmuseum.org/pleistocene-sea-level-maps" rel="nofollow noreferrer">https://www.fieldmuseum.org/pleistocene-sea-level-maps</a></p>
<p><a href="http://antiquity.ac.uk/projgall/sakellariou334/" rel="nofollow noreferrer">http://antiquity.ac.uk/projgall/sakellariou334/</a></p>
<p>Or you can even use <a href="http://geology.com/sea-level-rise/" rel="nofollow noreferrer">this interactive</a> map, which already does what you want to do, and compare it to past sea level.</p>
<p>As for why projecting backwards is easy, you may want to look up the term &quot;continental shelf&quot;.</p>

CC BY-SA 3.0
2017-08-20T23:19:08.953Z
2017-08-20T23:19:08.953Z
2020-06-18T08:25:19.090Z
John
<p>I am wondering how accurate such an approximation would be. I wish to take a current height map of the earth (including the ocean floor) and approximate the form of ancient landmasses by changing the sea level height.</p>

<p>I suppose this question could be answered by how much the ocean floor changes over time.</p>

<p>Timescales: Preferably over the last 200 000 - 300 000 years, but depending on the error of such an approximation, I am willing to settle for the last 10 000 - 15 000 years.</p>

<geology><earth-history><sea-level>
Approximation of ancient landmasses using current ocean floor data
Sapiens
# Approximation of ancient landmasses using current ocean floor data

(Asked by: username_0 on 2017-08-20)

I am wondering how accurate such an approximation would be. I wish to take a current height map of the earth (including the ocean floor) and approximate the form of ancient landmasses by changing the sea level height.

I suppose this question could be answered by how much the ocean floor changes over time.

Timescales: Preferably over the last 200 000 - 300 000 years, but depending on the error of such an approximation, I am willing to settle for the last 10 000 - 15 000 years.

**Tags:** geology, earth-history, sea-level


---

## 1 answers

### Answer by username_1 on 2017-08-20. Score: 1

over that short a time there would be very little change in the land itself, all you really get is a sea level change due to changes in the ice sheets, continental movement is barely noticeable.

such [measurements](https://en.wikipedia.org/wiki/Past_sea_level) and [maps](https://www.reddit.com/r/MapPorn/comments/6jm21e/global_coastlines_precatastrophic_sea_level_rise/) already exist.

here is the earth 12,000 years ago.
[![enter image description here](https://i.sstatic.net/aIRPI.jpg)](https://i.sstatic.net/aIRPI.jpg)

Here is the same map with the changes highlighted.
[![enter image description here](https://i.sstatic.net/0SxZr.jpg)](https://i.sstatic.net/0SxZr.jpg)

sources for other maps
<https://www.fieldmuseum.org/pleistocene-sea-level-maps>

<http://antiquity.ac.uk/projgall/sakellariou334/>

Or you can even use [this interactive](http://geology.com/sea-level-rise/) map, which already does what you want to do, and compare it to past sea level.

As for why projecting backwards is easy, you may want to look up the term "continental shelf".


---

