== Summary ==

Fan and Mortar Geysers are two [[geysers]] in the [[Upper Geyser Basin]] in [[Yellowstone National Park]]. These two [[geysers]], for the past several decades, have always erupted in concert with one another and are generally talked about together. The records detailing these geysers' known eruptive history shows that they have been infrequent and irregular performers.

== Location ==

The two [[geysers]] lie right of the edge of the [[Firehole River]]. Fan and Mortar Geysers are easily viewed from both the bridge and the sidewalk directly leading North to [[Morning Glory Pool]]. This area is just a bit North from [[Riverside Geyser]].

== Description ==

The two [[geysers]] lay on the edge of the [[Firehole River]], just like [[Riverside Geyser]]. However, both of the [[geysers]] are on the same side of the river, unlike Riverside. Mortar consists of the large [[Mortar]]-looking cone on the left. It consists of the vent in the cone, known as Upper Mortar, the vent right below it, known as Lower Mortar, as well as a additional smaller vent to the left of Lower Mortar. Fan consists of at least 7 vents aligned roughly perpendicular to the river. They are known as (starting closest to the river), River Vent(s), High Vent, Gold Vent, Gold 2, Angle Vent, Main Vent, and the East Vent. A numerous assortment of other vents are scattered through the area, as well as one other [[geyser]], close to the [[boardwalk]], known as Spiteful Geyser.

== History ==

Fan and Mortar's effect on the surrounding area, plus the size of their respective cones reveal that they were very active in the past. However, up until 1925, they were essentially two [[geysers]] that were very close to each other as their eruptive patterns were both independent of each other and were nowhere near the power of the [[eruptions]] of today. Some time preceding 1925, the two must have been eventually become connected at some depth and they have since performed as one very large [[geyser]]. Bryan, T. Scott. ''The Geysers of Yellowstone''. Niwot: University Press of Colorado, 2001. 119-120.

== Eruptive Pattern ==

The [[geysers]] follow a series of [[cycles]] prior to erupting. They are:

# A pause in which neither [[geyser]] is splashing,

# Surging in Mortar's lower vent,

# Jetting in three of Fan's vents,

# A return toward Mortar and another pause. Bryan, T. Scott. ''The Geysers of Yellowstone''. Niwot: University Press of Colorado, 2001. 121..

Generally the [[geysers]] are known to erupt during stage three, when Fan is currently splashing, although there have been eruptions that begin with Lower Mortar, and ever rarer: Upper Mortar. The geyser's eruption will become more powerful, eventually when all three main vents become steady eruptions. The eruption generally then begins when the water level in both geysers rises. Fan will show why its name is so deserved, as it erupts out of 7 different vents, creating a wide Fan-shaped jet that reaches heights of over 100 feet, and arcs water up over the [[boardwalk]], landing it 200 feet away from the vent. Mortar, while not as spectacular as Fan, sends jets out of its two main vents up to 50 feet high. Sometimes one vent will dominate the eruption sending a plume of water over 80 feet into the air. The eruption will generally last for around 15 minutes, until it stops, then restarts again, this time fading in power. It does this a few more times, until about 45 minutes have elapsed. It may then enter into a slight steam phase, where the geysers will send out brief puffs of [[steam]] out of their vents.

== Notes ==

== See Also ==

*[[http://www.geyserstudy.org Geyser Observation and Study Association]]

*[[http://www.nps.gov/yell/ Yellowstone National Park (U.S. National Park Service)]]

Notes: Will also include pictures, and two redirects from other inactive entries. Also the /ref command that is in the "<" and ">" is there, it just doesn't translate onto the blog.