The Sandy Glacier Caves are a system of

glacier cave A glacier cave is a cave formed within the ice of a glacier. Glacier caves are often called ice caves, but the latter term is properly used to describe bedrock caves that contain year-round ice. Overview Glacier caves form in the bottom edge ...

s within the

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Sandy Glacier Sandy Glacier is an alpine glacier located on the west slope of Mount Hood in the U.S. state of Oregon. It extends in elevation from about . The glacier is the source of Muddy Fork, a tributary of the Sandy River. The upper extent of the g ...

Mount Hood Mount Hood, also known as Wy'east, is an active stratovolcano in the Cascade Range and is a member of the Cascade Volcanic Arc. It was formed by a subduction zone on the West Coast of the United States, Pacific Coast and rests in the Pacific N ...

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

. They are thought to be the largest glacier caves in the

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states of the United States. Surveys done in 2011 and 2012 have measured the system at over 1 mile in length or about 7,000 feet. The caves formed from internal glacial melting at what are the headwaters of the Muddy Fork river. As melting continues, the caves grow larger with their entrances melting their way up the glacier's slope. Eventually it is predicted the caves will be completely gone within 7 to 10 years once the interior melting has reached the surface of the glacier. During early summer, all three surveyed caves within the glacier are connected through

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ice and are called the Snow Dragon Glacier Cave System. By late summer, the perennial ice melts away leaving only the disconnected glacier caves that have been individually named Snow Dragon, Pure Imagination, and Frozen Minotaur Caves. In 2013, a fourth glacier cave was discovered on the Sandy Glacier, but so far it has not been explored.

Exploration

The caves were first brought to the attention of Brent McGregor and Eddy Cartaya, both members of the

Oregon High Desert Grotto The Oregon High Desert Grotto (or OHDG) is an American caving club, known as a Grotto (National Speleological Society), Grotto. It is affiliated with the National Speleological Society. OHDG is involved with caving and conservation efforts in c ...

, when a video was posted on

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showing individuals at the entrance to a new glacier cave. Being ill-equipped, no exploration was done until McGregor and Cartaya explored the cave shortly thereafter with Scott Linn, and then returning to survey the cave which they coined Snow Dragon. Return trips led to the discovery of Pure Imagination Cave and then Frozen Minotaur. In 2012, the Oregon High Desert Grotto and other NSS members surveyed the entire system. In 2013, after numerous trips to the cave,

OPB Oregon Public Broadcasting (OPB) is the primary public media organization for the U.S. state of Oregon as well as southern Washington. It provides news, information, and programming via television stations, dozens of VHF or UHF translators, ...

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lead their most complex shoot to document the caves being studied by the grotto and scientists. As of October 2013, McGregor and Cartaya spent more than 300 hours mapping more than a mile of caves within the glacier. In 2016 it was reported that since 2014, McGregor's team the ''Glacier Cave Explorers'' has completed three expeditions to the glacier to map, photograph, and record environmental data. Their work in the caves discovered fir tree seedlings, duck feathers, and

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s. The team has brought glaciologists with them including Andrew Fountain, Jason Gulley and Gunnar Johnson.

History and science

The Sandy Glacier has lost about 40%, or almost half, of its ice between 1907 and 2004. The expeditions led by Cartaya and McGregor included Andrew Fountain to determine how much ice the glacier was losing per year by placing stakes on the surface. Internal temperatures in Snow Dragon Cave were measured at above 40 degrees Fahrenheit. Andrew Fountain believed the melting of the glacier is a sign that it was dying and in 5 to 10 years the caves would be entirely gone. In 2015 it was observed that a major portion of Snow Dragon had collapsed. The collapse of the caves continued with the majority of the caves being reported as entirely gone in 2016. The initial reason for their demise was reported as climate change, however other factors seemed to be contributing such as geothermal activity.

References

External links

Behind the Scenes of Glacier Caves: Mt. Hood's Secret WorldGlacier Cave ExplorersSandy Glacier Caves: Realm of the Snow DragonSnow Dragon Project
{{coord , 45.385 , -121.718 , type:landmark_region:US-OR_elevation:2300_dim:2000 , display=title Caves of Oregon Glaciology Glacial landforms Mount Hood Landforms of Clackamas County, Oregon