geysers.org

Revisited Hveragerði today, in order to visit some new areas and the revisit the activity there. The weather cooperated, as it wasn't too windy, there was no rain, and the sun even came out for a while, allowing for a backlit eruption video.

Found the locations of Grýla and Leppaluði, a couple of boreholes which erupted years ago. Grýla has its own little turnout along the road with a warning sign, even though it was overgrown and not at all steaming, and obviously not active in a long time. A 5cm wide hole in a rock, years ago it could be induced to erupt up to 10m high. Leppaluði is a circular concrete platform about 5m across that has been filled in, and also does not steam. But between it and the river was a small area of what appeared to be sinter gravel.

Farther north along the road is the Gufudalur golf course. Up on the hillside are several areas of thermal activity. In a ravine just outside are a couple of mudpot like features. In the course itself, between a couple of the hole is a thermal pond in which there was a spouter active. There's a sign, "Fallreitur" in front of it, which may be the name, or a warning for golfers. This feature really can only be see on the uphill side, and consists of an opening in a pennisula in the pond. Nearby were a couple of other muddy vents. (It seems this course and Arikikapakapa in Rotorua are the only courses with geothermal hazards.)

Farther up the hillside were another fairly dry mudpot and an old wellhead steaming away. I could not find the features Dirk Niermann calls "Lava Pool" and "Rey-8" and "Rey-9". Also did not try to locate Littli Geyser or Gosi I and II, as I couldn't find good descriptions of their locations. Seems Littli was up near the Agricultural Station we passed by on the way to hillside features the last visit.

We also revisited the Hveragerði Geothermal Park, mostly to see the eruptions of Eilifur Goshver/Eternal Geyser. This feature was nice an regular while we were there, with intervals within a few seconds of 20m15s. A quick burst of steam to 10 meters, but quite entertaining. The pool near the entrance also became active with eruptions when I was able to observe it.

There are reports of this feature only becoming active around 2016, and on the Apple Maps satellite view, there's a suspicious rectangular object located at that location. These satellite maps are several years old, based on the various new roads missing on them. The Google Maps satellite view shows a steaming area.

South of Húsavík is another Hveravellir. This one used to have several geysers, but all but one has been replaced by greenhouses.

The remaining geyser is Ystihver, a large raised bowl at the base of a hillside. It's about ten meters across, superheated and has been altered in several ways over the last century. There is a drain pipe which keeps the water level just below the rim. There are multple channels for the runoff.

The activity itself consists of periods of calm followed by a heavy boil or bursting. Some of the bursting can reach four meters high, and start with an explosive bubble. These eruptions put water out over the entire rim, and there are catch basins which we never saw water reach them, so it must be capable of even stronger activity on occasion.

On the south side is a concrete structure which has enclosed a small boiling feature, Strokkur. A couple of other geysers were similarly enclosed and are part of the greenhouse complex to the southwest. To the north are a couple of pyramids which contain well heads which are used to supply hot water to the town of Húsavík.

Today we visited Hverir, east of Myvatn in the far north. This is a place of mudpots, fumaroles and sulphur depositing solfataras.

Upon leaving the (paid) parking lot, the first thermal feature encountered is a watery mudpots with several areas splashing up about 1/2 meter. It lies at the bottom of a dominant feature of the area, a low scarp along which most of the solfataras are located. This scarp is about 100 meters long. Behind it, to the east are several large steaming mounds, which are the remains of boreholes drilled while exporing for geothermal energy.

West of the scarp are several distinct grouping of mudpots, ranging is style from the watery to the thick. All consist of a gray mud, in contrast to the reddish brown surface mud.

The largest, southern group has a number of spouters along the northern boundary, as well as some large muddy craters.

Up on the hillside of Namafjall are deep ravines from which a small trickle of clear water runs down toward the mudpots. Did not explore up that way, as it was a cool day and there was little steam visible up there.

Afterwards we had a wet, windy visit to Leirhnjúkur, which is a new thermal area which formed as part of the activity of Krafla in the 1980s. There is a large colloidal pool up on the hillside, with some spouters along the uphill shore and mudpots sharing the pools basin.

We also stopped at the thermal shower along the road south of the Krafla powerplant.

Today we spent about an hour at Deildartunguhver, a tiny thermal area northeast of Reyjavik. It consists of a single, wide fissure about 50 meters long that pours out boiling water from 10 major vents and numerous smaller cracks. It has been culturally modified to provide hot water for heating districts to the west.

(For identification purposes, I've tried to follow the numbering found in Niemann at Volcanic Springs. Unfortunately, he does not provide a map or photos of all the vents. I counted 10 vents, and based on his photo of #9, I think #10 became active after his visit.)

The vents are located in a wall at the base of Hverahóll, in two parallel lines. Some are about 1/2 meter up the side of the wall. Others are pools in the runoff channel, which eventually flows into the thermal district's intake.

The vents seem to be split into two groups, with five in each. Several The northnermost of the southern group, #5, is a pool in which I saw only occasional splashes. The rest of them spout continuously up to two meters (maybe even three) high from a crack in the wall.

The southernmost of the northern group, #6 is a geyser. It is a hole in the wall which spouts about 25-40cm most of the time. Every two to three minutes the activity increases in strength and the height approaches two meters. This continues for only a few seconds, then all activity and overflow ceases. The water in the vent drops from sight for a few seconds, then splashes start up down in the vent and the cycle continues.

The first stop of the day was at Hveradalir, located to the north of Route 1 west of Hveragerði. This is an area of frying pans, mudpots and fumaroles with a walkway through it on the edge of a well developed geothermal powerplant.

The walkway crosses a lagoon, which the information sign says is artificial. After that, the next main attraction is a large mud pot upslope from the walkway which has built a several meter high cone,and was in the process of occasionally flinging mud onto the walkway. Beyond that is a powerful fumarole and an eruptive feature. The latter is active inside a stone and cement box with a hole in the side which allows water to escape the box. The fumarole is loud, and I couldn't see any actual steam coming from it, a sign that it is highly superheated. To get to the end of the walkway requires passing through the fumarole' steamcloud, a slightly scary experience.

On the way back along the walkway, at the point where the walkway first crosses over the lagoon, we noted a small vent bubbling away. This activity was intermittent, and every minute or so it would increase to the point some splashes were getting to about 5cm high. Then the activity would cease for a few tens of seconds, only to start the cycle again.

The next stop was the Hveragerði Geothermal Park. I wasn't expecting much here as I knew about the changes after an earthquake 15 years ago when most of the pools empty and dried up. What I didn't expect was that there is an active, erupting feature there. It's probably artificial, and erupting borehole, but it is still a fascinating feature with a distinctive and unique eruption.

We saw four eruptions over about an hour period, the interval was about twenty minutes. There's just some rocks piled around the vent, probably the remnants of a borehole, and there is splashing about 1/2 meter high begins about five minutes after the eruption. This activity gets a bit stronger over then next fifteen minutes, but not by much. Suddenly, one of the splashes triggers an eruption, which lasts at most five seconds. There is a roar as water is expelled up to ten meters high, and just as suddenly drops down to nothing. According to the little map we got at the entrance, this is Eilifur Goshver/Eternity Geyser.

There's a second active feature, a small pool which splashes away and is located next to the cafe/greenhouse entrance to the park. It looks like it's probably a natural feature, as I didn't seen any evidence of concrete or other building materials around it. When I recorded the last eruption we witnessed, I decided I wanted a distant shot, so was standing about 25 meters from the Eilifur with the small pool in the foreground. As the eruption started, the pool suddenly increased in activity and force and the splashing was well over a meter high for just as long as the eruption lasted. Then it reverted back to its previous splashing.

The next stop was a thermal area up on the hillside north of town. Over about 100 meters is a line of mudpots and acidic springs. At the northern end are signs with names for some of the features: Reykjamóri, Leirgerður and Skjálfti. Based on these, I think it was Skjálfti that was having eruptive episodes. This feature contained opaque, brownish red water which was boiling up and splashing from every locations. Every minute or two the activity would get stronger in one of the vents, and the splashing would be one or two meters high.

The final stop of the day was to see Littli Geyser at Gamla Laugin/Secret Lagoon in Fluðir. It, along with several other boiling springs, are on the grounds of the spa and provide some of the waters used.

The vent is maybe 25 cm across, and there are two deeply incised runoff channels leading from it. Most of the time there is water flowing down one of these channels, and the vent is in a constant agitation to maybe 25cm high.

Based on an hour and a half's observations, Little has three sizes of eruptions. The minor is shorter and not as tall, and the vent almost immediately resumes overflow and splashing. The larger eruption lasts longer, is taller and the vent drops below overflow and refills over about a minute. The major eruption is the tallest and longest, with some of the eruption getting to about four meters high. After the eruption the vent drains with the usual array of sounds.

All but one series consisted of two minor eruptions about two minutes apart, and then two minutes after that, a major eruption. It takes about five minutes between a major and the next minor. The time we saw the intermediate eruption, it was after the first minor eruption, and it was followed by another minor and then a major.

Near Litli are some deep boiling springs. One had collapsing bubbles at the bottom, maybe 1/2 meter below the surface. There's also another boiling spring, Vaðmálahver between the spa and the Litlà-Laxa River.

Visited our first Iceland thermal features today. Gunnuhver sits in the middle of a production geothermal field. The activity consists of a perpetual spouter which has jets of water up to 8 meters high. The vent is obscured by the remnants of a boardwalk which it destroyed earlier this century.

Nearby is a large mound of siliceous sinter. It's old and heavily eroded, but there are still rock fragments featuring flow patterns and terracettes.

To the west of the recent volcanic activity is Seltún, south of Kleifarvatn. There's a large parking lot along with plumbing facilities which may or may not be open.

Next to the parking lot is a large muddy spring which was erupting gray water to about 1/2 meter. A boardwalk trail continues up the hillside past more large acid sulphate springs and numerous small spouters.

Across the road is another small thermal area consisting of two large mudpot craters. They were more of a pool than a mudpot, probably thanks to the heavy rains in the couple of days prior to our visit.

Behind the plumbing facilites is an old geothermal well. When I first looked at it, there was occasional noise coming from below ground as it there was some sort of eruption going on. About twenty minutes later, I stopped by again and the feature was quiet.