Geology: Etch-A-Sketch Ice Sheets

Geologists have lots of time to play with.

About 4,540,000,000 years worth according to the latest estimates.

Luckily, geology discovered the Etch A Sketch in the 1960s.

The Etch A Sketch toy was invented in the late 1950s by André Cassagnes, in his basement. He called it “L’Ecran Magique”, the magic screen.
In 1959, he took his drawing toy to the International Toy Fair in Nuremberg, Germany.
The Ohio Art Company saw it but had no interest in the toy.
When Ohio Art saw the toy a second time, they decided to take a chance on the product.
The L’Ecran Magique was soon renamed the Etch A Sketch and became the most popular drawing toy in the business.

Simply put: the Etch A Sketch revolutionised geology.


When a group of geologists encountered a nice big fat juicy erratic boulder they whipped out their Etch A Sketch screens and quickly draw a massive ice sheet to explain away the presence of the erratic boulder.

A glacial erratic is a piece of rock that differs from the size and type of rock native to the area in which it rests. “Erratics” take their name from the Latin word errare, and are carried by glacial ice, often over distances of hundreds of kilometres. Erratics can range in size from pebbles to large boulders such as Big Rock (15,000 tonnes or 17,000 short tons) in Alberta.

An ice age, or more precisely, a glacial age, is a period of long-term reduction in the temperature of the Earth’s surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers.

The geologists then selected the best Etch A Sketch image to put in the geology textbooks.

This wasn’t an easy task because they originally had 4,540,000,000 blank years to choose from.

However, to make it look like they were really beginning to make progress with the history of the Earth they decided so paste the same image over 100,000 years and call it an Ice Age.


Unfortunately, having the same image repeated on 100,000 pages was very boring because the Ice Age narrative had neither beginning nor end.

However, being stout fellows and brilliant academics, the geologists agreed to overlook this criticism of their literary style.

But, after all their efforts, there were still 4,539,900,000 empty pages in the geology books.

Luckily, one very bright geologist decided to refer back to the Etch A Sketch instruction manual.

There, to his amazement, he discovered a quick shake of the wrist would reset the Etch A Sketch.

This was another truly revolutionary discovery for geology.

With a quick shake of the wrist geologists could erase the past and start drawing a new picture.

However, just to make sure that nobody thought they were cheating the geologists decided to call this new discovery an Interglacial period.

Furthermore, being very ingenious, the geologists decided to cover their tracks by topping and tailing the Ice Age with Interglacial periods that were 11,400 years long.

This further enhanced their reputation because the Interglacial periods filled in more blank years.


An interglacial period (or alternatively interglacial) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene interglacial has persisted since the end of the Pleistocene, about 11,400 years ago.

Buoyed up with their success [and mastery of the Etch A Sketch] the geologists wanted to start drawing lots of lovely new ice sheets that would pad out the geology books still further.

However, remembering the previous literary criticisms the Geologists decided to introduce a few new characters into their narrative.

Firstly, being poets and scholars, the geologists introduced the fair maiden Moraine.

A moraine is any glacially formed accumulation of unconsolidated glacial debris (soil and rock) which can occur in currently glaciated and formerly glaciated regions, such as those areas acted upon by a past glacial maximum. This debris may have been plucked off a valley floor as a glacier advanced or it may have fallen off the valley walls as a result of frost wedging or landslide.

Secondly, the geologists [after a few pints of Guinness] introduced the wicked Baron Drumlin.

A drumlin, from the Irish word droimnín (“little ridge”), first recorded in 1833, is an elongated hill in the shape of an inverted spoon or half-buried egg formed by glacial ice acting on underlying unconsolidated till or ground moraine.

The geologists then embarked upon the wholesale creation of new Ice Ages and Interglacial periods. What fun!


Overwhelmed by their success the geologists introduced a third character to spice up the story.

Thus, the cold hearted King Proglacial, facilitated another stream of best sellers for the geologists.

In geology, a proglacial lake is a lake formed either by the damming action of a moraine or ice dam during the retreat of a melting glacier, or by meltwater trapped against an ice sheet due to isostatic depression of the crust around the ice.


The rest, as they say, is history.

The Ice Ages stories still don’t have any beginning or end.

But, like all good fairytales, they do have some awfully good Etch A Sketch illustrations.

This entry was posted in Catastrophism, Earth, Geology, Glaciology, Inventions & Deceptions, Science, Water. Bookmark the permalink.

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