Like a one-man Google Earth, Swiss aviation pioneer Eduard Spelterini
flew a gas-filled balloon from the French town of Chamonix to
Switzerland on August 8, 1909 – a distance of 100 miles over the Alps.
While the flight was extraordinary for being the first aerial crossing
of the central Alps from west to east, it now holds a special
significance of which Spelterini was unaware. The balloonist was also a
photographer who captured a series of glass-plate images of the Mer de Glace (“sea of ice”) glacier that descends from the Mont Blanc Massif in a dramatic sweep.
Spelterini’s interest in recording the alpine landscape was both scientific and aesthetic, and the results are striking. This collection
of images survives today as a record of the glacier that is unique in
its detail and antiquity. But crucially, they can be used to measure how
much this landscape has changed in the intervening years. In 1909, no
one could have guessed how significant these glaciers would become to
environmental science, or just how rapidly they would be affected by rising temperatures in the century that followed.
Digital analysis
The flight over the Mer de Glace was unusual because Spelterini’s
aerial photographs rarely focused on the glaciers, instead more often
framing the peaks and other geological features. He was also unaware
that the distribution of his photographs along the balloon’s flight
path, pictured below, would make excellent material for digital analysis
more than 100 years later.
The flight path of Eduard Spelterini’s balloon in 1909.James Gentles, Author provided
By identifying common features in the photographs, which can in turn
be linked to surveyed features in the landscape, a 3D representation of
both the balloon flight and the historical topography can be
reconstructed using photogrammetry
– the science of taking measurements from photography. While the
oblique angle of the photographs limits the measurable accuracy of the
resulting data, compared to the vertical mapping photographs taken in
the decades that followed, they still provide a unique and compelling
glimpse into a past landscape.
In Spelterini’s image below, the oblique aerial view taken at a
sideways angle towards the horizon gives a sense of place that is part
way between the familiar ground level view and the high vertical
perspective like that of a map. In the foreground the newly completed Montenvers cogwheel railway
is visible, perched over the voluminous Mer de Glace glacier which
leads the eye to the spires of the Mont Blanc Massif in the background.
The Montenverscog railway in the foreground was recently completed when Spelterini took this photograph.Eduard Spelterini, Author provided
The photographs are carefully composed, designed to serve as both
record and artwork. Their oblique angle makes them less abstracted and
more relatable, despite their height above the ground and the scale of
the landscape they depict. All of these factors make them an ideal point
of reference for visualising the changing nature of the alpine
landscape.
Follow that balloon
In October 2017, a team of photographers and researchers from the
University of Dundee returned to Chamonix to replicate the path of the
historic flight and recreate the sequence of photographs using a
helicopter. Spelterini’s balloon rapidly ascended to around 2,000m above
the Chamonix valley before passing Mer de Glace. Such heights are
virtually inaccessible to unmanned drones, meaning that a manned
aircraft was needed.
The results are documented in The 100-year Time-Lapse Project.
GPS coordinates derived digitally from Spelterini’s photographs were
used to return to the same locations to capture current-day equivalents
of both his individual photographs and the 3D surface reconstruction.
While the rate of change in the Mer de Glace glacier has been studied
in great detail, using digital technology in this way allows for a
visual comparison of the landscape then and now to reveal the staggering
reduction in the ice surface that has taken place over the last
century.
Kieran Baxter and Kieran Duncan/YouTube.
Today, visitors alighting at the Montenvers railway station are no longer confronted with the Mer de Glace at close range,
but instead look down upon a largely empty valley and debris-covered
glacier far below. Here the ice surface has dropped around 100 metres
compared to its height in 1909. Scientists have calculated that, overall, the glacier has lost around 700m cubic metres of water since the beginning of the 20th century.While the facts and figures alone should be enough to narrate the
impact that the previous century of greenhouse gas emissions have had on
our climate and environment, images like these help drive the point
home. Eduard Spelterini was not just a pioneer of aviation but also of
aerial photography as a way of better understanding the natural world.
His images capture an emotive sense of place while providing insights
into aspects of the landscape that are not available from the ground.
Kieran Baxter/YouTube.
Today, despite the heavy carbon footprint that comes with manned
aviation, we continue to rely on aerial views to interpret our
environment, from Landsat satellite
imagery to low-level drone photography. By repurposing archival aerial
photographs and continuing the legacy of photographers like Spelterini,
with the help of current technology, we can explore new and compelling
ways to visualise our rapidly changing glacial landscapes.As well as serving to convince hearts and minds in the present
political debates surrounding climate change, these images will also
form a poignant record of magnificent landscapes that will no longer be
around for future generations to experience.
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