On the shelf

Continental shelves make seaside paddling possible, but it hasn’t always been so . . .

Poor Pangea felt she could stand it no more,
With tension and stress everywhere;
So she faulted and rifted, creating sea-floor,
And hot mantle rock mended the tear.

Her new continent edges, now stretched out and thinning,
Were moved ever further apart.
The sea flooded in, and from this beginning
A new ocean appeared on the chart.

Then wind, waves and rainwater each had their way,
Bringing sediment down all the while;
So the continent shelf soon sloped gently away
With a fall of nine feet in each mile.

When ice last lay heavy and deep on the land,
The sea level fell like a stone
Exposing the shelf, so life could expand
To make this new landscape its home.

But glacials don’t last for ever. The sea
Soon returned as the temperature rose.
(Beneath it, there’s oil, coal and gas: not for free –
As they’re used up, their mining cost grows).

Our insular status was thus re-conferred.
But, should a new glacial come by,
Then Selsey would think that its prayers had been heard,
For its caravan parks would stay dry!

[Images: www.scotese.com (top); scienceandthesea.org (centre); BBC News/Dee Caldwell (bottom)]
This entry was posted in Uncategorized and tagged , , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *