The Shetland Islands

Next stop on this trip was the Shetland Islands - the northernmost part of Scotland. We anchored off of the largest city, Lerwick. It has a population of about 7,000 but I did not experience it as I selected a trip that moved south along the east shore of the North Sea to an archaeological site called Jarlshof. Near there, we hiked a short distance to Sumburgh Head, a spectacular sheer cliff with a lighthouse that faces the Scottish mainland.

Map of the destinations on this 8-day trip - Glasgow, Fort William, Portree, Orkney's, Shetland's
and Sognefjord

Map of the Shetland Islands and Sumburgh Head

Coastal drive along the North Sea

The North Sea on a calm day south of Lerwick

Beaches such as this were used by Late Neolithic and Bronze Age people on the islands

Jarlshof

An aerial photo of Jarlshof, taken from an interpretive sign on site. South is at the top and the various occupation
periods are color coded to the timeline shown in the next photo. The oldest sites are to the right in pink and date to
2500 to 800 BCE (Before Common Era, or the former BC). Adjacent to this is the orange-outlined roundhouses dating
from 500 to 200 BCE, followed by the yellow-colored habitation at 100 BCE; dark-green wheelhouses from 0-500 CE
(Common Era or formerly AD); dark blue outline at the top is Viking age 850 to 1275 CE; the farmhouse in dark grey
upper right from 1300 to 1500 CE; and the large house outlined in white was occupied from the 1590s to about 1700 CE.
Over 4500 years of occupation are revealed at this site, first exposed by erosion in 1890.

The wheel of time at Jarlshof

The oldest roundhouses are from the Late Neolithic, perhaps as old as 2700 BCE.

From an interpretive sign, an artists impression of an early Bronze Age roundhouse

Ruins of the interior of a wheelhouse from about 0 to 500 CE

Artists rendition of the interior of an occupied wheelhouse

Looking down on an excavated wheelhouse

These are the remains of the Viking occupation from about 850 to 1275 BCE

Sumburgh Head

Out next destination of Sumburgh Head as viewed from Jarlshof

On our way to Sumburgh Head, the southernmost point on the Shetlands

This is a working lighthouse with included residence, historic diesel engines and coffee shop

The Old Red Sandstone makes up the tilted layers 

Many vessels have become shipwrecks at Sumburgh Head and one of the most famous was in January 1993 when
the oil tanker MV Braer ran aground in a violent storm 

I got some great exposures of Atlantic puffins and summer flowers

Looking north along the west coast of Shetland

The upturned sandstone beds are the result of the Caledonian Orogeny, when Laurentia (ancient North America) collided with Baltica (ancient Scandinavia) and Avalonia (ancient southern Great Britain. However, a rather obvious wave-cut(and uplifted) beach terrace provided a convenient parking place for the coach!

Sailing out of Lerwick on our way to Norway!

Oil platforms in the North Sea. I'll be posting spectacular images of Norwegian fjords next time and
there will be more about the Caledonian Orogeny which is well expressed there.

Scotland's Orkney Islands

After leaving the Isle of Skye, Le Champlain rounded the northern tip of the Scottish mainland and came to anchor on the western side of the Orkney Islands. I had landed here previously in 1991 and held fond memories of the history and Bronze Age archaeological sites we visited on these windswept islands. I did not have as good of an impression from that visit of the Shetland Islands but that may have been due to the rainy weather experienced back then, because it was an outstanding visit this time.

The Orkney Islands

Stromness

Picturesque Stromness with a population of only 2,500

A view over the Stromness rooftops to a lighthouse - I walked through hilly neighborhoods in a light rain

I couldn't help but notice the tropical plants at this far northern latitude, the warm Gulf Stream in action

Driving along the shore toward Kirkwall, Le Champlain lies at anchor

Another view of the Mainland – yes they call the largest island in this chain the Mainland

Kirkwall

Kirkwalls' Cathedral of Saint George, constructed of the Old Red Sandstone

On the cathedral's arched doorway, note the alternating and  
beautifully colored sandstone blocks

On closer inspection, you can see what is likely salt-weathering
in the blocks. Salt mist blows in from the sea and is deposited on
the outer surface of the stone. Then salt crystals grow on the rock,
prying apart the sand grains - that is salt-weathering!

The nave of the cathedral

Near the altar, a tomb for famed Arctic explorer John Rae is found. It reads, "
Arctic Explorer Intrepid discoverer of the fate of Sir John Franklin's last expedition;
Born 1813; - Died 1893;
Expeditions -1846-47; 1846-49; 1851-52, 1853-54. Read more about John Rae here.

The tomb in the church is vacant - he is buried in the church graveyard

Late afternoon light in the Cathedral of St. George graveyard 

The Ring of Brodgar

Our last stop was to the Ring of Brodgar, a Neolithic stone circle and UNESCO World Heritage site

The stones used in the henge are upright slabs of the Old Red Sandstone - read more about this famed
rock unit here

The interior of the circle has never been excavated but it is estimated to have been constructed between
4500 and 4000 years ago, about the same age as the Pyramids at Giza

It was originally comprised of 60 slabs but only 27 remain standing

This is classified as a ritual landscape with other important sites nearby
that have been recently discovered

This concluded my one day visit to Mainland Orkney
and it was time to sail to Shetland!

The July 23, 2024 Hydrothermal Blast at Yellowstone National Park

The Yellowstone Volcano Observatory has issued a report on the hydrothermal blast in the Biscuit Basin area of the Park on July 23. I have copied their news release in its entirety here. It was NOT a volcanic eruption, but rather water turning to steam at shallow depths.

Damaged boardwalk near the steam blast (Creative Commons courtesy of Yellowstone NP)

YELLOWSTONE VOLCANO OBSERVATORY INFORMATION STATEMENT
U.S. Geological Survey
Wednesday, July 24, 2024, 3:43 PM MDT (Wednesday, July 24, 2024, 21:43 UTC)

YELLOWSTONE (VNUM #325010)
44°25'48" N 110°40'12" W, Summit Elevation 9203 ft (2805 m)
Current Volcano Alert Level: NORMAL
Current Aviation Color Code: GREEN

This is an update on the hydrothermal explosion that occurred just before 10 AM on Tuesday, July 23, in Biscuit Basin, Yellowstone National Park.

National Park Service (NPS) field crews have completed a preliminary assessment of the conditions following the hydrothermal explosion at Black Diamond Pool. For a map showing the locations of the features in that area, see https://www.usgs.gov/media/images/map-major-features-biscuit-basin-yellowstone-national-park. 

What happened?

The July 23, 2024, hydrothermal explosion at Biscuit Basin resulted from water suddenly transitioning to steam in the shallow hydrothermal system beneath Black Diamond Pool and was not caused by volcanic activity. Seismicity, ground deformation, and gas and thermal emissions remain at their normal background levels, and there were no detectable precursors to this event. 

The explosion, which sent steam and debris to a height of hundreds of feet above the ground, destroyed a nearby boardwalk and ejected grapefruit-sized rocks tens to hundreds of feet from the source. Some blocks closest to the explosion site are about 3 feet (1 meter) wide and weigh hundreds of pounds. The explosion was largely directed to the northeast toward the Firehole River, and the largest blocks of debris fell in that direction. The dark color of the explosion was a result of mud and debris mixed with steam and boiling water. Although visitors were present at the time of the event, no injuries were reported.

Black Diamond Pool and Black Opal Pool were affected by Tuesday’s explosion, and while they remain distinct features, the shape of Black Diamond has changed somewhat. Both pools are murky due to debris, and the unstable ground around their edges occasionally slides into the water. Just after the eruption, Black Diamond Pool exhibited minor roiling and water spouting. The water level in the pool rose over the course of the day, and by Tuesday afternoon the roiling transitioned to occasional bursts of hot water that reached about 8 feet (2.4 meters) in height.

What is happening now?

By Wednesday morning, July 24, the levels of Black Diamond Pool and Black Opal Pool had risen enough that both were overflowing and sending murky water into the Firehole River. No water bursts from Black Diamond Pool were witnessed Wednesday morning. 

What are ongoing hazards?

Given the recent changes to the hydrothermal plumbing system, small explosions of boiling water from this area in Biscuit Basin continue to be possible over the coming days to months. USGS and NPS geologists will be monitoring conditions, mapping the debris field, and sampling water to assess any changes in the shallow hydrothermal system over the next several days.

Hydrothermal explosions typically occur in the park one to a few times per year, but often in the back country where they may not be immediately detected.

Similar, although smaller, hydrothermal explosions took place in 1989 at Porkchop Geyser in Norris Geyser Basin, and on April 15, 2024, from the Porcelain Terrace Area of Norris Geyser Basin. A small hydrothermal explosion occurred from Wall Pool, in Biscuit Basin, in 2009. Significant hydrothermal explosions, probably similar in size to that of July 23, 2024, occurred in the 1880s at Excelsior Geyser, in Midway Geyser Basin.

Yellowstone National Park has closed Biscuit Basin for the remainder of the 2024 season for visitor safety. Grand Loop Road remains open to vehicles, and other nearby thermal basins, like Black Sand Basin, are open. Additional Yellowstone National Park information about visitor access can be found at https://www.nps.gov/yell/index.htm. 

More information

Yellowstone Volcano Observatory monitoring website: https://www.usgs.gov/volcanoes/yellowstone

2022-2032 YVO Monitoring Plan: https://pubs.usgs.gov/publication/sir20225032

Preliminary Assessment of Volcanic and Hydrothermal Hazards in Yellowstone National Park and Vicinity: https://pubs.usgs.gov/publication/ofr20071071

Yellowstone National Park images from Biscuit Basin explosion site: https://www.flickr.com/photos/yellowstonenps/albums/72177720319112324/

The Yellowstone Volcano Observatory (YVO) provides long-term monitoring of volcanic and earthquake activity in the Yellowstone National Park region. Yellowstone is the site of the largest and most diverse collection of natural thermal features in the world and the first National Park. YVO is one of the five USGS Volcano Observatories that monitor volcanoes within the United States for science and public safety.

YVO Member agencies: USGS, Yellowstone National Park, University of Utah, University of Wyoming, Montana State University, EarthScope, Wyoming State Geological Survey, Montana Bureau of Mines and Geology, Idaho Geological Survey 

Journey to Scotland with Smithsonian Journeys

Recently, I was fortunate to represent the Smithsonian Institution's travel program, Smithsonian Journeys, as a geologic lecturer for 145 guests. We sailed from Glasgow Scotland to Bergen Norway, stopping at six delightful and very scenic destinations. What an honor it is to represent the Smithsonian in this way and to further a wider understanding of earth history and modern-day earth processes to the traveling public! This post just covers the first two stops in Scotland - I will post the rest of Scotland and Norway in subsequent posts.These are the three formal lectures I gave onboard:

1. Landscapes and Geology of Scotland: The Birthplace of Modern Geology

2. Through Time in the Orkney and Shetland Islands

2. Fjords and Glaciers of Norway and Earth’s Changing Climates (plus - Short History of the Smithsonian) 

There was also the opportunity to visit with guests individually while onshore with observations and insights. The voyage traveled through landscapes containing rocks as old as 3 billion years (the Lewis Gneiss) to Paleogene lava's (about 60 million years old). A highlight for me was learning more about the Caledonian Orogeny, when North America collided with Baltica (ancient Scandinavia) and Avalonia (ancient France and Iberia). This mountain building event commenced about 430 million years ago.

Glasgow

I barely made the ship's departure! My flight to the UK from Phoenix was delayed 21 hours (not cancelled) and other delays caused me to arrive at the ship terminal just before the gangway was lifted. It was quite the adventure.

From the desert of Arizona to green, green Scotland - this is Glasgow

Sailing down the River Clyde from Glasgow - I missed seeing this most interesting city

Fort William and Loch Ness

Fort William is a pleasant town on the Atlantic side of Scotland

A view northwest along "strike" of the Great Glen Fault, which has experienced multiple but
opposing episodes of offset beginning with the Caledonian Orogeny between 430 and 390 Ma
(Mega-annum or millions of years ago). Note the linear line of cliffs on the left and the orientation
of the canal which parallels the fault's strike slip offset. 

Satellite view of the Great Glen fault in winter (image courtesy of the
Geological Society of London)

Later in the day while transiting the loch, the boat's video screens displayed the linear bathymetry
of Loch Ness, which has a maximum depth of 755 ft. We did not see a swimming reptile.

View to the northwest on Loch Ness, which is 23 miles long. The Great Glen Fault is the most
prominent fault in all of Great Britain.

Isle of Skye

Skye is the northernmost and largest island of the Inner Hebrides chain. It has a rich human history dating back to the Mesolithic (in Scotland this dates to about 14,000 to about 5,500 years ago). The scenery is rugged with deep bays and prominent peninsula's.

Our visit began anchored off of Portree, the largest town on Skye at about 2,200 residents. It is
known for its colorfully painted pier buildings.

As we toured the edge of the island, we could see cliffs of layered basalt

The hummocky terrane seen behind the white houses is a gigantic landslide with blocks of rotated rock
sliding from left to right (west to east)

As we drove around the island, we encountered sheer basalt-lined
cliffs, this one with a waterfall

Turning to the south, extensive cliffs were seen. The lava's erupted in the Paleogene, about 60 Ma.

We also visited Dunvegan Castle

My next posting will cover the Orkney and Shetland Island groups. Stay tuned!