Tolting Around Pseudocraters at Lake Myvatn, Iceland

The Lake Myvatn area, located in northeast Iceland, has an amazing, and truly beautiful, volcanic landscape. This area lies within Iceland’s North Volcanic Zone, which is a part of the Mid-Atlantic Ridge – the spreading rift between the Eurasian and North American plates that slices through Iceland. Lake Myvatn is the fourth largest lake in Iceland, and is quite shallow, with the deepest part being only about 4 meters. This area is also renown for its wetlands and birdlife, with the lake’s numerous bays and its outlet to the north-flowing river Laxa being host to a multitude of birds.

Lake Myvatn, viewed from the lake’s eastern side.
Basaltic landscape in the Hofdi area, on the southeast side of Lake Myvatn. Hofdi is a rocky promontory into Lake Myvatn that affords excellent bird watching.
Lava pillars in the Kálfastrandavogar area, southeastern Lake Myvatn.

My favorite experience at Lake Myvatn was riding an Icelandic horse around the pseudocraters in the Skútustaðagígar area of Lake Myvatn (southwestern part of the lake). Pseudocraters are unusual in that they are rootless volcanic cones that formed in this area about 2300 years ago when basaltic lava flowed over the water-logged lake sediment, resulting in the cones being built from steam exploding through the lava. So -not only did I want to see pseudocraters, but I also wanted to lean how to tolt because this is a natural gait exclusive to Icelandic horses. According to Riding-Iceland.com,

“the Tölt is a natural, fluid gait of the Icelandic Horse, during which at least one foot always touches the ground. Foals often tölt in pastures at an early age. The tölt is an extraordinarily smooth four-beat gait, which allows the rider an almost bounce-free ride, even at 32 kmh (20 mph). “

I contacted Safari Horse Rental (located just off the main road in the Skútustaðagígar area) and set up a two hour ride. Gilli was my guide, and he took me through mostly private land to both look at pseudocraters and to teach me how to tolt. It did take me awhile to understand how to let my horse know it was time to break into the tolting gait, but when we both got it figured out, wow! what a way to see pseudocraters! I’d urge anyone who loves to ride horses to try this!

The start of the pseudocrater exploration ride at Safari Horse Rentals!
A pseudocrater looms ahead of us. The pseudocraters are typically composed of tephra, scoria, and splatter that resulted from basaltic lava flowing over water-logged lake sediments forming steam eruptions that blast through the lava.
The remnants of a pseudocrater becomes a watering hole for the area sheep herds.
Basalt block fences are common on Icelandic farm lands.
This photo shows midges covering a part of a pseudocrater. The midges weren’t numerous when I was at Lake Myvatn, but they periodically emerge by the billions to cover the Lake Myvatn area. In fact, Lake Myvatn means “midge lake” in Icelandic. The midge populations are very closely tied to the Lake Myvatn fishery. Unfortunately, dredging in the lake during the 1960’s for a silicon mining operation has probably caused enough fluctuation in the midge populations to result in the collapse of the fishery. See the following publication for more information on this – High-amplitude fluctuations and alternative dynamical states of midges in Lake Myvatn.

Again – I’ll highly recommend that the best way to view Lake Myvatn’s pseudocraters is by tolting on an Icelandic horse!

Iceland Geology – Snorkeling the Silfra Fissure, Thingvellir National Park

I did a snorkel tour of the Silfra fissure with Dive.is while I was in Iceland a couple weeks ago. That is a very impressive way to view part of the mid-Atlantic ridge system! Here’s what Dive.is says about Silfra that makes it so unique:

Snorkeling the Silfra Fissure in Iceland.

“Silfra is a fissure between the North American and Eurasian tectonic plates in Thingvellir National Park. The rift was formed in 1789 by the earthquakes accompanying the divergent movement of the two tectonic plates . The diving and snorkeling site at Silfra is right where the two continents meet and drift apart about 2 cm per year. Silfra is the only place in the world where you can dive or snorkel directly in a crack between two tectonic plates. The earthquakes of 1789 opened up several fissures in the Thingvellir area, but the Silfra fissure cut into the underground spring filled with glacial meltwater from the nearby Langjökull glacier.”

My Silfra snorkel group starting out in the fissure with our guide Jake from Dive.is.

There are 6 people to a group for the snorkel tour, with each group accompanied by a guide from Dive.is. Jake was our guide and he was great! The tour is simply snorkeling through basalt and more basalt, but with the water clarity, the colors are beautiful. There is also one place where you can stretch across the fissure and basically touch both plates.

The start of the snorkel tour where the entrance platform can be seen in the background.
The stretch between plates…
This is where basalt really looks grand!
Near the end of the snorkel tour, the fissure opens into a shallow lagoonal area.
The colors in the sandy lagoon are just as spectacular as elsewhere in the fissure. The exit platform can be seen in the distance.
The end of the snorkel tour – ours was a great weather day, so even though the fissure water is cold (we all wear dry suits with long underwear and two pairs of wool socks), I could have snorkeled around the lagoon for a long time.

I also took video while I was snorkeling, so am inserting a clip from the first part of the snorkel tour at the end of this blog. The video clip includes the time when we all get geared up, have our gear checked, and then flipper-walk down the entrance ramp, into the water. We all have to do a flip over to our back once we’re in the water, just to make sure we can maneuver once we’re in the water. The clip continues on as we snorkel through the first several minutes of exploring the fissure. At the end of the snorkel tour, we hike back to where the Dive.is vans/equipment are. After taking off our gear – which getting off the dry suit is somewhat of a challenge – we have hot chocolate and cookies. Because the weather was so nice, it was a pleasurable experience to stand around and feast. But – we were told that in the wintertime the guides take the hot water that is suppose to be used for the hot chocolate and it pour down the snorkelers’ necks so the dry suits can be pulled off. Glad I opted for late May to do this!

Yellowstone To Southwest Montana Autumn Field Photo Snaps

Montana’s autumn is my favorite time of the year to do field work. Daytime temperatures are usually cool enough to encourage one to keep moving and the lighting is simply gorgeous. It is also one of the best times to visit areas in and around Yellowstone National Park (YNP) because most of the tourists have gone home. So no huge bear traffic jams or jostling for parking spots at the better known thermal spots in YNP and surrounding environs – it’s just a wonderfully introspective time for field forays. What follows are several photos that chronicle some of my fall wanderings in the greater Yellowstone area, both in terms of wildlife and geology.

Some of my favorite sightings in YNP are bison at any time of the year. But the autumn snows bring on the bison’s technique of using its head to clear snow away from any vegetative food source. The result of their snow-clearing activity is a snow-masked face.

Snow-caked face of a bison in YNP portends the winter food retrieval.

Snow-masked bison near Soda Butte Creek, YNP.

And where the snow hasn’t stacked up much, the YNP bison calmly graze and occasionally congregate on a ridge line to watch what remains of the YNP visitor traffic.

YNP bison contemplating passing vehicles.

Geological features in YNP take on new dimensions with the golden low and slanting light of autumn. I’ve spent much time re-photographing geologic features at all scales that seem to glow in this season’s light.

Tertiary sediments and Quaternary sediments/basalts of “The Narrows” cliff face adjacent to the Yellowstone River, northern YNP. Columnar basalt capped by auto-brecciated basalt makes a morel-like image for these geological units.

An early morning at -7 F on the Lamar River with steam fog resulting from the fall’s chilled air moving over water still warmed from summer.

A rodent trackway disappears into microterracettes of Palette Springs, Mammoth Hot Springs, YNP.

Microbial growth near the proximal part of Mound Springs, Mammoth Hot Springs, YNP.

The proximal end of Mound Springs abounds in various colored microbial life. It’s hard to stop photographing these features because they are so intriguing!

The lipped margin of Mound Spring’s pond facies, Mammoth Hot Springs, YNP.

The fall staging areas of sandhill cranes in southwestern Montana are mesmerizing. Staging areas are those locations where cranes annually congregate during late September into October, spend several days foraging through fields for food, and eventually continue on their migration southward from Montana to Colorado and the southwestern U.S.. The staging area that I usually go to is near Dillon, Montana, where hundreds of cranes can be viewed.

Sandhill crane interaction during their fall staging near Dillon, Montana.

Sandhill cranes doing a dance routine in the Dillon, Montana staging area.

As I said initially, it’s hard to surpass a Montana/YNP autumn!

Tertiary geology and paleontology of the central Gravelly Range – a project update

The 2017 field crew working at Lazyman Hill. The strata are late Eocene (probably 34-36 million years in age) tufa deposits.

It’s time for our yearly update talk on field work and data compilation for the Tertiary geology and paleontology of the central Gravelly Range project in southwestern Montana. The Madison Ranger District in Ennis, Montana (5 Forest Service Road) will be hosting my talk on Monday, April 2nd at 10am in the Madison Ranger District conference room. We have a project permit from the US Forest Service because our project area lies within the Madison Ranger District – and the USFS District people have been really helpful with our project logistics. Thus, this is the perfect way to let them know what we did this past field season and how the whole project is coming together. The Madison District just sent their public announcement for the talk:

Dr. Hanneman and Dr. Don Lofgren, PhD (Director, Raymond M. Alf Museum of Paleontology, Claremont, CA 91711) and their team have been executing a multiyear study in the Gravelly Range near Black Butte resulting in many interesting paleontological findings right here in our own back yard.  Please join Dr. Hanneman and the Madison Ranger District for an update on this project and what they hope to unearth this year!

It’s a very intriguing project on high-elevation, mainly Eocene-Oligocene Tertiary geology and paleontology (mostly vertebrate and floral). So – anyone with an interest in this and who is in the geographic area, is welcome at the talk!

Winter Trekking Through Yellowstone’s Thermal and Glacial Features

Cross country skiing in one of the glacial melt-water channels on the Blacktail Plateau.

Some winter days in Yellowstone National Park are so amazing with clear blue skies and sparkling snow that they just take your breathe away. Luckily enough, I just experienced several of these kinds of days which I packed full of cross country skiing, snowshoeing, and animal watching.

One of the groomed trails that held a good snow base until about early afternoon is the Blacktail Plateau Loop. The trail follows melt-water channels that are associated with “Retreat Lake”, which was formed by the Beartooth glacial ice mass blocking the lower end of the Grand Canyon of the Yellowstone during the Pleistocene.

Rounded cobbles and boulders left behind from melt-water flow sit on the volcanic bedrock in many areas along the trail. Ski tip in the lower right for scale.

Looking back to the northwest on the Blacktail Plateau ski trail. Notice the scoop-shape of the landscape which is the result of this area being part of a glacial melt-water channel.

Calcite Springs overlook is accessible during the winter via the Tower ski trail.

The Tower ski trail provides access to the Grand Canyon of the Yellowstone area. A favorite stop of mine is the Calcite Springs overlook where the thermal springs lie south of the overlook, on the west side of the Yellowstone River and Pliocene/Pleistocene sediment and basalt are on the Yellowstone River’s east side.

 

A groomed ski trail also accesses the Upper Terraces of Mammoth Hot Springs. However, after a few days of spring-like temperatures, the snow was so melted back that I just used my snowshoes to trek through the icy slush.  Some thermal features were still covered by snow and slush, but others appeared much more vibrant against the white snow/slush blanket.

One of the fissure ridges along the upper Terraces trail is called White Elephant Back Springs and Terrace.

Aphrodite Terraces lie a short way north of the White Elephant Back Springs:

My favorite thermal feature of the Upper Terraces is Orange Spring Mound. The spring is supported by a fissure ridge and is intermittently active. Because of its low water discharge and subsequent slow growth, it has built up a characteristic cone shape.

Orange Spring Mound of the Upper Terraces in Mammoth Hot Springs.

All in all, it was perfect wintertime fun trekking around in Yellowstone. Can’t wait to get back there when the bears come back out from hibernation!

 

Home Heating With Volcanic Heat

Volcanic heat from Icelandic volcanoes may end up heating British homes. The UK government has signed a memorandum of understanding with Iceland to further study this option. The project would be technically challenging. Electricity produced from the geothermal energy would go to the UK via an underwater cable that would be at least 620 miles long. Icelandic officials say that the project could be in place by 2020. Read more at: Icelandic Geothermal Energy