Friday, April 30, 2021

Melting Glaciers

One of the most visible effects of global heating is the extraordinary reduction in the size of the world's glaciers. Because of the rise in temperatures around the world glaciers are melting at an increasing rate, which could have a dramatic effect on the planet. Melting glaciers contribute 20% of global sea level rise and around a quarter of the world's population depends on water released from glaciers. 

The Guardian newspaper has created a very effective animated visualization which shows the extent that 90 of the world's largest glaciers have shrunk in size over the last 40 years. In Visualised: glaciers then and now The Guardian uses an animated small multiple visualization to show the size of 90 glaciers today compared to the size of the same glaciers 40 years ago. The 90 small maps of individual glaciers clearly shows the dramatic effect that global heating has had in just 40 years on the size of glaciers around the world.

One of the most beautiful and effective visualizations of glacial retreat is Timelines. Artist Fabian Oefner has created two outstandingly beautiful images from the heartbreaking effects that global heating is having on the world's glaciers. Using historical data of glacial retreat Oefner has released two interactive photographs which visualize how Switzerland's Rhône and Trift Glaciers have shrunk in size over the last 140 years.

Timelines by Fabian Oefner consists of two interactive nighttime photographs - one of the Rhône Glacier and one of the Trift Glacier. Superimposed over the image of each glacier are lines which show the glacier's maximum extent for each year. Both of the photographs are interactive. If you move your mouse over either photo the lines are added or removed from the image by year. The effect is an astonishingly beautiful but extremely worrying visualization of how each glacier has shrunk over the years.

To create these interactive images of glacial retreat historical data was used to plot the maximum expansion of each glacier during each year between 1874 and 2017. Drones were then flown along the line of maximum expansion for each year. These drones flew at night - lit up by LED lights. The artist Oefner then photographed the LED line of maximum expansion created by the drone for each year from a vantage point high on a mountain top above the glacier.

The result is two extraordinarily beautiful images of the dreadful results of global heating.

In 2017 the Swiss newspaper Tages Anzeiger visualized the extent of Switzerland's shrinking glaciers over the last 160 years. In So Schmolzen die Schweizer Gletscher in 160 Jahren Weg the paper produced a series of multiple maps visualizing the change in size of the country's 38 largest glaciers. Tages Anzeiger reports that the Rhône Glacier has shrunk by 4.7 km² or about 23.4% in size over the last 160 years. Over the same period of time the Trift glacier has shrunk by -4.6 km² or around -23.8% in size.

CBC News' How a melting glacier could redefine the Alberta–B.C. border uses a 3d map of the Haig glacier to show how the glacier is retreating and causing a shift in the border between B.C. and Alberta.

Disappearing Glaciers is an Esri StoryMap designed to highlight the alarming speed at which glaciers are disappearing around the world. This map looks at recent aerial imagery of six different glaciers.

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