Winter visitors to Yellowstone National Park who were fortunate enough to be in the Old Faithful area last week were treated to a rather rare display by Giantess Geyser—the large geyser's first reported eruption in well over two years.

The eruption began about 2:55 p.m. on Wednesday, January 29, and immediately caused considerable excitement for fans of these amazing geothermal features. The last such display was in September 2011, and although Giantess' infrequent eruptions used occur several times a year, activity has become somewhat less frequent and unpredictable in recent years.

Information from the park says "Infrequent but violent eruptions characterize Giantess Geyser. This fountain-type geyser erupts in several bursts 100 - 200 ft (30 - 60m) high.... The surrounding area may shake from underground steam explosions just before the initial water and/or steam eruptions. Eruptions may occur twice hourly and continue for 4 - 48 hours."

One of the Largest and Loudest Geysers in Yellowstone

According to the Geyser Observation and Study Association (GOSA), "Giantess is one of the largest and loudest geysers sometimes reaching well over 200 feet and being heard over a mile away. Unfortunately, it is relatively rare ...To complicate matters even more, it is also quite variable in the strength of its eruptions. People that have only heard about its very powerful eruptions are often disappointed if they see one of its lesser shows. They shouldn't be since even these are quite a sight but when you are expecting great height and noise, a shorter quieter eruption can be a disappointment."

According to information from the park, Giantess is just one of "Numerous hot springs and more than 40 geysers ...located on the right bank of the Firehole River across from Old Faithful. Giantess Geyser dominates Geyser Hill. When this geyser is active, many of the other hydrothermal features change their behaviors, an indication that many of these features are interconnected."

Giantess Geyser is located in an area known as Geyser Hill and is included in the Old Faithful Area Online tour on the park website; the geyser's location is shown on the map at this link. Old Faithful is perhaps the best-known of the park's geysers, but several others, including Giant Geyser, Grand Geyser, Beehive Geyser, and Giantess Geyser can all be bigger than Old Faithful when they erupt.

Cathy Bell is a ranger at Yellowstone, and living nearby gave her the chance to capture the following short video showing part of the recent eruption the day after it began. She reports that this display by Giantess lasted about 40 hours, and most of the activity had ended by Friday morning. You'll find some great photos of other recent geyser activity at Yellowstone on her blog.

In 2008, Park Ranger George Heinz gave a live, on-line talk about the "Personalities and Myths of Geysers," which included these comments at Giantess:

Giantess is the "Grand Old Lady" of Geyser Hill

" The grand old lady of the hill is where the steam is at the top of the mound, right before the trees, directly behind me... It’s a massive geyser. Since it’s a fountain geyser, all that water is not directed out of a cone straight up. It can shoot at many different angles. It’s a burst this way, a burst that way. It’s pretty impressive. It also shows up as an earthquake on the USGS. The first time I saw Giantess erupt I was in the Old Faithful Inn there about 29 – 28 years ago and it shook the building. It’s a massive geyser and you can feel the ground around here shakin'."

If you'd like a real-time glimpse at what's happening right now at Yellowstone in the vicinity of Old Faithful, check out the "Old Faithful Geyser Live!" webcam. "This full-motion, live-streaming webcam is located near Old Faithful Geyser and brings online visitors views of several other geysers in the area. When geysers such as Beehive, Lion, or Giantess are erupting, the camera will be aimed at them and zoomed in for optimal viewing enjoyment. When bison, elk, coyotes, or the occasional bear wander into the camera's view, live video images will be transmitted."