Watch: Yellowstone's Ear Spring Has Rare Eruption, First Activity of Its Size Since 1957

Yellowstone National Park is having a particularly busy summer when it comes to thermal activity with multiple geyser eruptions, including a rather rare one at Ear Spring.

Ear Spring, located in the Upper Geyser Basin, got its name because of its shape, which resembles a human ear. While it's traditionally quiet, on Saturday, visitors observed a rare eruption at the geyser. The moment was captured on camera by the Geyser Observation and Study Association and smoke was seen billowing up towards the sky from the ground.

Although rare, the water eruption certainly did not disappoint and the United States Geological Survey (USGS) reported water reached heights of 20 to 30 feet. Along with rocks, the eruption unearthed some long lost treasures from the park's many years of visitors.

"The eruption ejected not only rocks, but also material that had fallen or been thrown into the geyser in years past, like coins, old cans, and other human debris," the USGS wrote.

ear spring yellowstone eruption
Ear Spring after an eruption of water and debris on Saturday. The surrounding bacterial mats have been destroyed and large rocks are strewn around the area surrounding the spring. United States Geological Survey

Ear Spring usually remains docile and the last known eruption that was similar in size to Saturday's occurred in 1957. But smaller eruptions have occurred as recently as 2004, and the new activity led to a closure of the park's boardwalk.

Along with Ear Spring, several other geysers located on Geyser Hill, just across from Old Faithful, Yellowstone National Park's most famous hot spot, exhibited unusual behavior.

West of Pump Geyser and north of Sponge Geyser, directly under the boardwalk, a new feature formed, which erupted overnight on Tuesday into Wednesday. An area of the ground surrounding the feature, reaching about eight feet in diameter, is rising and falling about six inches every 10 minutes.

Doublet Pool and North Goggles Geyser also experienced an increase in geysering and boiling. Despite the level of activity, the USGS utilized Twitter to make it abundantly clear that a volcanic eruption was not in the cards at the moment.

#Yellowstone is NOT about to erupt (now that's out of the way).

Changes afoot in @YellowstoneNPS
#UpperGeyserBasin. Water eruption of #EarSpring (photos, before & after) on Saturday, Sept 15 & other features on #GeyserHill behaving strangely. Read more:

— USGS Volcanoes🌋 (@USGSVolcanoes) September 19, 2018

The USGS also explained that changes in hydrothermal features at Yellowstone are common and aren't synonymous with changes in the activity of the volcano.

"Shifts in hydrothermal systems occur only the upper few hundred feet of the Earth's crust and are not directly related to movement of magma several kilometers deep," the USGS said. "There are no signs of impending volcanic activity."

It's unclear at the time what the changes on Geyser Hill will mean but the USGS identified two likely possibilities. One possibility is that the area surrounding the thermally heated ground will continue to expand and cause changes in hydrothermal activity for years. If this occurs, the current boardwalk would need to be rerouted.

Another possibility is that a small hydrothermal explosion could occur, which would form a crater a few feet wide. If the small eruption happens, it would eject rocks and hot water up to a distance of hundreds of feet.

ear springs yellowstone
Ear Spring, located on Geyser Hill in the Upper Geyser Basin. Old Faithful can be seen steaming in the background. United States Geological Survey

Along with the activity coming from the ground, Yellowstone National Park had some unusual activity stemming from one of its visitors over the weekend. On Friday, Ashely Lemanski posted a video on Facebook of a man standing on top of Old Faithful with the caption, "a rare occurrence at Old Faithful."

A woman can be heard in the video screaming at the man, who was standing on the geyser with his legs spread, to get on the boardwalk. At one point, the man got on his stomach and seemingly put his face into the smoke coming from the geyser.

"Get off Old Faithful," the group of tourists can be heard screaming to the man before he walked away from the geyser. Park rangers found the man after he eventually made his way back onto the boardwalk and cited him with walking off the boardwalks in a thermal area.

Yellowstone National Park is the world's first national park and was established in 1872 by then-President Ulysses S. Grant. Almost four million people visit the national park each year, with the months of June, July and August being the most popular times.