The objectives of this paper are to investigate the tradeoffs between a
physically constrained neural network and a deep, convolutional neural
network and to design a combined ML approach (“VarioCNN”). Our
solution is provided in the framework of a cyberinfrastructure that
includes a newly designed ML software, GEOCLASS-image, modern
high-resolution satellite image datasets (Maxar WorldView data) and
instructions/descriptions that may facilitate solving similar spatial
classification problems. Combining the advantages of the
physically-driven connectionist-geostatistical classification method
with those of an efficient CNN, VarioCNN, provides a means for rapid and
efficient extraction of complex geophysical information from submeter
resolution satellite imagery. A retraining loop overcomes the
difficulties of creating a labeled training data set.
Computational analyses and developments are centered on a specific, but
generalizable, geophysical problem: The classification of crevasse types
that form during the surge of a glacier system. A surge is a glacial
catastrophe, an acceleration of a glacier to typically 100-200 times its
normal velocity, which for a marine-terminating glacier leads to sudden
and substantial mass transfer from the cryosphere to the oceans,
contributing significantly to sea-level-rise. The sudden and rapid
acceleration characteristic of a surge results in formation of
crevasses, whose spatial characteristics provide informants on the
ice-dynamic processes that occur during the surge. GEOCLASS-image is
applied to study the current (2016-2024) surge in the Negribreen Glacier
System, Svalbard. The geophysical result is a description of the
structural evolution and expansion of the surge, based on crevasse types
that capture ice deformation in 6 simplified classes.