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Geysers of the World   

Geysers of Yellowstone   



  Depression Geyser
Feature Type: Geyser
Geyser/Spring Type: Fountain geyser

Upper Geyser Basin
Geyser Hill

Depression is a small fountain-type geyser. Heights range from 4 to 10 feet, durations are about 5 minutes and intervals in recent years have ranged from 8 to over 12 hours. Depression erupts from a small but deep and pretty pool. Depression's activity was greatly affected by the 1959 Hebgen Lake earthquake and the 1983 Borah Peak earthquake. Both earthquakes caused its intervals to decrease. After the earthquakes, over a period of years, the intervals have slowly increased.

What to look for:
It takes Depression about 90 minutes to refill after an eruption. Once overflow is reached, the water level will fluctuate slightly but overflow rarely stops. Just prior to the eruption, small bubbles can sometimes be seen rising near the middle of the pool. During some years, these bubbles start rising just before the eruption. More recently though, bubbles have started rising hours prior to the eruption. The eruption starts with heavy overflow. This is my favorite part of the eruption. After about a minute of heavy overflow, the eruption starts in earnest. There are two main vents that can be involved in the eruption. One vent is in the center of the crater and the other is in a small alcove in the right side of the crater. This second vent often kicks in towards the end of the eruption and throws water, at an angle towards the opposite side of the crater. This water rarely makes it out of the now nearly empty crater. After the eruption. the crater is empty.

Electronic Monitor Files
Depression eruptions for 1997.txtDepression eruptions for 1998.txt
Depression eruptions for 1999.txtDepression eruptions for 2000.txt
Depression eruptions for 2001.txtDepression eruptions for 2002.txt
Depression eruptions for 2003.txtDepression eruptions for 2004.txt
Depression eruptions for 2005.txtDepression eruptions for 2006.txt
Depression eruptions for 2007.txtDepression eruptions for 2008.txt
Depression eruptions for 2009.txtDepression eruptions for 2010.txt
Depression eruptions for 2011.txt 

Some of the temperature data used to derive the eruption times and durations used in this section were collected by Ralph Taylor under a National Park Service research permit, and the remainder was collected by personnel working for the Geology Department of the Yellowstone Center for Resources (including Ralph Taylor). The loggers are a combination of loggers owned by the NPS and Ralph Taylor. Analysis of the raw temperature data to extract the eruption data was performed by Ralph Taylor. The eruption time files on this website may be used provided that Yellowstone National Park is credited for the temperature data and Ralph Taylor is credited for the eruption times.

Activity Recorded by Data Logger - by Ralph Taylor  

Depression Geyser has been monitored electronically since 1997. Data from 1997 to mid-2002 covers only the summer months, generally from late June to early October, but since the mid-2002 we have attempted to monitor Depression all year. There are three large gaps in the record, 27 Dec 2002 to 1 Feb 2003, 2 May 2003 to 22 June 2003, and 27 Oct 2003 to 21 Jan 2004. Two of these were caused by the logger going missing (presumably because of critters) and one because of a logger filling its memory. A short gap from 24 to 27 May occurred in 2008 when the logger memory filled. The 2009 and 2010 record is complete.

In October 2009 Depression's intervals shortened to the three hour range and became less variable. These shortened intervals continued into 2010. During 2010 and early 2011 Depression's intervals have gradually increased.

Activity in 2011  
The overall statistics for 2011 are shown at Depression Geyser 2011 Statistics. A pdf of this summary is at Depression Geyser Recent Activity Summary.

The interval graph shows all of the recorded intervals for 2011. The graphs for the current year are updated about every six weeks from October to June and weekly from June to the end of September. The yellow triangles show the eruption start times for Little Squirt Geyser. The Little Squirt eruption times are used as a surrogate for the so-called SMax (South [Geyser Hill] water level MAXimum), which is thought to represent a cyclic change in the hydrothermal energy on Geyser Hill. This hypothesis is described in an article in GOSA Transactions Volume IV titled Cyclic Hot Spring Activity on Geyser Hill, Upper Geyser Basin, Yellowstone National Park—Graphical and Interpretive Descriptions of the Geyser Hill Wave, Diurnal Effects, Seasonal Disturbances, Random (Chaotic?) Events, and Earthquakes by T. Scott Bryan. The green diamonds show the first eruption of each recorded Dome Geyser series. Activity in Dome geyser is also known to affect some other features on Geyser Hill.

In October 2009 Depression's intervals shortened to the three hour range and became less variable. These shortened intervals continued through all of 2010 and into 2011.

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The next graph shows the intervals for the past few months at an expanded time scale.
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The graph to the left shows Depression Geyser intervals for the last month.
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The next graph is a histogram of the distribution of intervals. Note that in this and the other histograms displayed here the labels shown on the X-axis represent the upper boundary of the class, not the midpoint. Geyser times are traditionally truncated. The graph at the right has class widths of 10 minutes. The bar appearing above the label "2:20," for example, contains intervals from 2h11m through 2h20m.
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Finally, the graph at the right shows the monthly minimum, mean, median, and maximum intervals.
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Activity since 1997  
Depression's activity was been monitored only in the summer months from 1997 to 2002, so the full cycle is not shown on the graphs. The first graph shows all of the intervals recorded since 1997. The intervals show an increase in 2002, reaching a peak in late summer or early fall, then dropping to 7-8 hours until late 2003 when a rising interval trend began that continued until early 2006. The peak occurred around September-October 2006 with numerous intervals over 24 hours and many in excess of 30 hours. The trend reversed in 2007 as intervals fell below 12 hours during the summer months, then rose at the end of 2007. In 2008 the intervals initially returned to the 12-18 hour range, but by June started a dramatic rise to peak at over 100 hours, or fewer than two eruptions per week. The intervals again dropped late in 2008, but began to rise in early 2009.
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The pattern shows up more clearly in the moving one-day median interval graph .
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The final graph shows the monthly minimum, mean, median, and maximum intervals for all of the data available. This gives another view of the changes over the past decade. People who watch Depression can attest to the difficulty in catching an eruption in the past few years. Hopes that the drop in the maximum and average intervals in early 2007 heralded a return to more predictable eruptions of this underappreciated geyser proved unfounded. Indeed, by late summer of 2008 Depression had become a rare geyser indeed.
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Activity in 2010
Activity in 2009
Activity in 2008
Activity in 2007
Activity in 2006
Activity in 2005

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Please note - this site is currently under constuction. Please visit for more information.  Last update 01-29-2017

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