Month: February 2023

When the ‘solid’ ground moves

My hubby and I have experienced al kinds of strange phenomena on our travels, and I have to say that an earthquake was the eeriest. We walk around on this earth expecting it to stay put, and when it doesn’t it’s unnerving.

Ontario, the province I live in, experiences very mild tremors from time to time, but every level upward on the Richter scale is incrementally more powerful. The earthquake we were in while visiting friends in California a number of years ago was 4.6, and while no one got hurt, our immediate instinct was to find an aircraft and get the hell off the ground (very different from the way we felt after our aborted flight to Milford Sound in New Zealand years later, when the turbulence was so bad I literally wanted to kiss the ground in relief upon landing).

I can’t even imagine the feeling of a 7.8 quake, which according to the old seismic scale created by Charles Richter and Beno Gutenberg in the 1930s, would be 30 times stronger that the one we went through. Photos in news media, and the enormous loss of life, tell the actual story.

Our minor quake started as a rumble, as if a large truck was coming down the road, and that’s what we thought it was. But instead of passing by the house of our friends, where we were staying, it just seemed to keep coming and coming. One of our friends jumped up to hold the china cabinet in place and keep it from toppling over, which in retrospect was unlikely – but one of the worst things about earthquakes when they begin is you have no idea how bad they’re going to be.

We were warned not to go outside, where those pretty red clay Californian roof tiles tend to pop off like lethal frisbees. The best thing to do was find a part of the house with the most structural integrity, as in a bathroom (all the pipes in the walls) or any cased doorway.

Riding it out, the initial quake felt like it went on forever, but was less than a minute. Our friends were used to it; we were quite freaked out. Then the aftershocks began, and trickled on for hours. Some were very subtle (it was Christmastime, and occasionally we could see the tree ornaments jiggling even though we couldn’t feel anything), others were startling, as if a gigantic creature kicked the house and shifted it a few inches. We had visions of great cracks opening in the ground (thanks, Hollywood!), which didn’t happen at the time, but they certainly have in Turkey.

In Turkey and Syria, it was the buildings themselves that were the danger, by all accounts for one main reason: they hadn’t all been built to code. The quake took place on February 6th, and by the 12th, 113 arrest warrants had been issued to contractors and others in the building industry for failing to follow quake guidelines. According to BBC News, experts in Turkey had been warning for years that many new buildings were unsafe due to corruption in the industry as well as government policies that, in order to encourage a construction boom, allowed contractors to circumvent the regulations. And of course, it’s been largely the innocent public who’ve paid the price, over 30,000 of them dying in Turkey and more than 5,000 in Syria as rescuers work frantically to try and recover them under hundreds of pounds of rubble.

Earthquake-proofing a building, or a city, has been studied extensively since the famous San Francisco quake in 1906. Little was known about the mechanics and geology of earthquakes in that time. Based on modern scales that have superseded the Richter model, the quake was likely around 7.9 – a major shake that flattened buildings never meant to withstand such stresses.

San Francisco Earthquake of 1906: Ruins in vicinity of Post and Grant Avenue. Looking northeast. By Chadwick, H. D – This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing., Public Domain, https://commons.wikimedia.org/w/index.php?curid=2128556

To make matters worse, fires broke out all over the devastated city, and the water supply for fighting them wasn’t up to the task.

San Francisco, and all of California, lie along the enormous San Andreas Fault, 750 miles of trouble. Californians straddle the geographic wrestling match between the world’s two largest tectonic plates:

the Pacific Plate (covering almost the entire bottom of the Pacific Ocean, 40 million square miles), which is moving steadily in a northwest direction, and the North American Plate (29 million square miles, covering most of North America, down into the Caribbean and eastward across a good portion of the Atlantic Ocean), which is moving southwest but is forced into a southeastward direction by its massive neighbour. Photos of the Fault look like a nasty scar on the landscape.

Aerial photo of the San Andreas Fault in the Carrizo Plain; By Ikluft – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=3106006

The earthquake in Turkey and Syria occurred along the fault between the Anatolia and Arabia Plates, with the top edge of the Africa Plate just a short distance south. The two major fault lines created by this juxtaposition, have a slip rate of 1/4 inch to almost 1/2 inch a year. The San Andreas Fault’s slip rate is substantially greater, at more than 3/4 inch, but California’s building codes are much stronger.

So how does one make a building as quake-proof as possible?

Well, I can tell you that the Incans in Peru did it quite well. The Spanish invaders regularly built their churches and other buildings on top of Incan walls – and when the next earthquake came along, the Spanish structures fell down and went boom while the Incan constructions remained serenely intact. The 2007 earthquake in Peru, along the central coast, measured 8.0. In the town of Pisco, right in the middle of the quake, you can see how it damaged an old church on the town square, to the point where the building became unusable and a new church had to be constructed beside it. Fortunately, the fast-moving Nazca and South American Plates (3 inches per year), stayed put while we were there, and the only shaking anyone might have felt was after a few stiff Pisco Sours.

The secret of Incan construction was huge stone blocks interlinked with holes matched up with protrusions that locked the walls together. Their civilization was brilliant at creating long-lasting structures.

Incan wall showing remnants of the original construction details – protrusions and holes that fitted together to lock a wall into place, taken at the Museo Inka in Cuzco, Peru – E. Jurus,all rights reserved

For modern buildings, keeping them standing during a quake depends on the size of the building. Average wood-framed homes in California can apply to be retrofitted to make them sturdier. The “Earthquake Brace + Bolt (EBB)” system involves bracing any ‘cripple’ walls (walls 4’ or less between the frame and the foundation) in the crawl space under the house (no basements in California) with plywood sheaths to strengthen them, and then using large anchor bolts to connect the wooden frame to the concrete foundation. It’s all designed to keep a house from sliding off its foundation during a quake. The retrofit also straps in the home’s water heater, which can tip over and damage water lines, gas lines and electrical wiring. Contractors have to be trained by FEMA (the U.S. Federal Emergency Management Agency).

Multi-storey buildings have their foundations put on what’s called ‘seismic base isolation, using isolator bearings of layers of rubber and steel with a lead core. These reduce the amount of vibration a tall building experiences. It’s remarkably effective – you can watch a video demonstration here. Buildings may also contain steel-plate shear walls and other damping materials that reduce the lateral movement of the structure.

Something like 80% of all the major earthquakes on Earth occur around the volatile Ring of Fire – basically the edges of the Pacific Plate. Here in Canada, it’s lovely British Columbia that suffers the brunt of the Ring of Fire’s ire. Our government’s website has information and instructions on what to do should you find yourself in the throes of a good shake.

  • If you’re inside, stay there and “Drop, Cover and Hold On” – drop under sturdy furniture like a desk or a bed, cover your head and torso to protect against falling objects, and hold on tight to whatever you’re under.
  • Stay away from windows and shelves with heavy objects.
  • If you can’t find something strong to hide under, crouch or flatten against an interior wall.
  • If outside, stay there and move away from any buildings BUT if in a crowded place find some cover so you’re not trampled.
  • If in a vehicle, pull over safely and avoid blocking the road. Avoid anything that could collapse on or underneath you, like bridges and overpasses/underpasses. Stop the car, stay inside, and listen to the radio for emergency instructions.
  • In general, avoid: doorways with doors that might slam shut and hurt you; bookcases and other tall furniture that can easily fall over on you; elevators; coastlines (tsunamis are triggered by earthquakes).

The site also has instructions on how to make your home as safe as possible if you live in an area prone to substantial quakes, and what to do after the quake has happened.

It took my hubby and I thirteen years to work up the nerve to return to California (if you knew our track record with bizarre travel adventures you’d understand), but we’ve been several times since and – to date – haven’t experienced another one. We were also lucky in Peru just a few years after the 2007 quake and in New Zealand (which just had a 6.1 quake on February 13th), where we watched the city of Christchurch on South Island still rebuilding from two bad quakes in 2011. Is our luck running out? We may find out in British Columbia when we visit for Storm Season – not sure when, but it’s on my bucket list.

‘Bergy’ Tidbits

Ice forms on Niagara Falls when it’s cold enough – photo by E. Jurus

My family lived on a farm north of Lake Superior for a couple of years when my brother and I were kids, so I’m very familiar with cold and snow. Our small community usually saw the first snowflakes fall before Halloween, spent all winter under a feet-thick white blanket, and didn’t see grass until April. I remember that the coldest day we saw during that time registered at -52oF (before Canada switched to the Celsius system), and there were a number of days when either the teacher (who lived in one of the towns at least 30 minutes away in good weather), or we students, or both couldn’t make it to school because the roads were clogged with snow.

But that life pales in comparison to what the people in Newfoundland experience, ranking in the top dozen lists of Most Snowfall (outside the Rocky Mountains in British Columbia), Biggest Blizzards and Most Days with Snow on the Ground (Snowiest Places in Canada). Newfoundland also sits somewhat enviably on the edge of Iceberg Alley, where the massive frozen chunks we call icebergs break off glaciers in Greenland and make their way southward along the prevailing currents until they eventually melt in warmer waters.

It was one of those icebergs that gouged out the starboard side of the enormous ship Titanic on the evening of April 14, 1912 and sank the world’s most famous passenger liner. Not the way the crew and passengers wanted to go down in history, by any measure.  

Icebergs are strange creatures, so much so that many places speak of them almost as if they’re alive. When they break off from their parent glacier in spring and summer, the process is called ‘calving’, and the hundreds of bergs that drift down the eastern coast of Canada are referred to as an annual migration.

Although the icebergs travel through salty ocean waters, they themselves are composed of the purest water on Earth – most of them, anyway. There are big sheets of frozen salt water that form in fall and winter around Greenland, and also break up into chunks when the thaw sets in.

Officially, though, an iceberg is a piece of freshwater ice at least 15 metres long (about 49 feet) with 5 to 15 metres (16 to 49 feet) sticking out above the water’s surface. that chunked off either a glacier or an ice shelf and floats about in open water. These pieces of ice are classified by size: bergs are either small, medium, large or very large – imagine coming face to face with a behemoth over 600 ft long and 246 tall. And because almost 90% of an iceberg’s mass is below water, you’d dearly want to avoid the part you couldn’t see!

Smaller chunks of ice from between 5 to 15 metres long are called ‘bergy bits’, while those smaller than that are called ‘growlers’. They’re all dangerous. If you think of how much the Ice Age glaciers transformed North America as they moved, carving out lakes and mountains, you get a sense of how, despite the size of the early great transatlantic liners (the RMS Titanic was 971 feet long), in a collision it was the iceberg that was the ‘immovable object’.

The iceberg that the Titanic ran into was believed to have been, according to eyewitness reports, between 50 to 100 feet tall and 200 to 400 feet long. The below-water section of it, which is what tore open the huge gash in the ship’s hull, may have been half a mile in length (over 2500 feet). When the ship’s spotters first observed the gigantic piece of ice headed straight for them at 11:39pm on that fateful night, it was only about 900 feet away, i.e. practically on top of them. Only 30 seconds later, the ship felt the impact as the helmsman frantically tried to get out of the way but the iceberg slowly ground its way past.

News quote from the era, Titanic Museum, Belfast Northern Ireland – photo by E. Jurus

So when you read about the modern-day men in Newfoundland who snag and fish out such huge chunks of ice, usually weighing several tons, (“The Iceberg Cowboys Who Wrangle the Purest Water on Earth”, “Iceberg harvesting is a swashbuckling new industry in Newfoundland and Labrador”), you may wonder if they’ve lost their minds. Many of the bergs they harvest have calved from the very same glacier that produced the one that sank the ‘ship that couldn’t be sunk’, Sermeq Kujalleq. The Titanic ran into its destroyer in Iceberg Alley, when the ship had almost made it all the way across the Atlantic and was already telegraphing Newfoundland’s Cape Race station to announce its impending arrival in New York.

The slipway where the RMS Titanic was launched on its doomed voyage is marked with the placement of the huge lifeboats that only rescued a few of the 2,240 passengers, Belfast, Northern Ireland – photo by E. Jurus

The Titanic disaster is one of the most studied in history, but still remains an enigma. That year there was an abnormally large number of icebergs in Iceberg Alley. Numerous sightings by other ships were radioed or telegraphed to the Titanic but the captain ignored them and didn’t reduce speed. And many wonder why the spotters didn’t sight the behemoth until it was too late to avoid.

The intrepid berg catchers go out in large fishing boats and with any luck can clamp an iceberg and slowly feed it through a grinding machine into storage tanks. But if the boat can’t get close enough (remember the nasty part hiding in the dark sea waters), they have to transfer to a small motorboat, wrap it in a net, haul it on board the bigger boat and hack it up into chunks. It seems to be fairly lucrative work – the pure water apparently has an amazing taste (if the taste is anything like the water we kids used to scoop out of streams that ran across those farms up in northern Ontario, I believe it – I’ve never tasted anything as wonderful since) and is used for premium Iceberg Vodka, Iceberg Beer, bottled water and fizzy ice cubes. In 2016 Newfoundland introduced a tax on iceberg harvesting.

I’d love to visit Antarctica, where 93% of the world’s mass of icebergs float around, just to see the magnificent beasts. (For some wonderful photography, check out this article in the National Geographic Resource Library Iceberg.) That’s a very expensive trip, though. A better option might be to travel to Greenland, where you can also go iceberg-watching. There you can see 5 kinds of ice:

  • White ice, which is relatively young with many air bubbles that allow light through and give it the dazzling snowy colour
  • Blue ice, which is older, from the Greenland Ice Sheet. It’s heavier, more compressed, and with a blue cast.
  • Black ice, which is clear but looks black as it floats on the water. It’s feared because it’s so hard to spot and because its weight drags the most dangerous part below the surface, where it lies in wait for unwary ships.
  • Dirty ice, which has accumulated mud and sand from blowing storms.
  • And there are the aforementioned saltwater ice chunks to content with as well.

A late friend of mine was lucky enough to hear and see an iceberg calving many years ago. When hubby and I were in New Zealand, checking out Mt. Aoraki, we witnessed several small avalanches and were struck by how noisy they were – I can only imagine the sound of an entire berg leaving home. Maybe one day we’ll get to witness it for ourselves.

In the meantime, here are a few fascinating facts about the babies that attack ships:

Different shapes of icebergs
By Romain – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=114073584
  • Each year, between 10,000 to 15,000 icebergs are calved, most of them from the Antarctic continent, which also produces the largest glaciers.
  • The ice in icebergs can be more that 15,000 years old.
  • Icebergs can contain up to 10% air bubbles by volume, and when the bubbles are released as the bergs melt, they make a fizzing sound called ‘Bergie Seltzer’.
  • We tend to think of icebergs as huge chunks just floating placidly through the water, but as they melt they can actually flip over, or even capsize. The largest bergs can create earthquakes as powerful as an atomic bomb.
  • One can tell if an iceberg is going to flip if any birds sitting on it suddenly take flight. It’s believed that the birds have such a keen sense of balance that they can detect gradual movements in icebergs long before people can see them.
  • Along with white, blue, black and dirty, icebergs can also be green, yellow and striped, depending on their water composition and algae that might be inside.
  • Icebergs are also classified by their shape: tabular (with steep sides and a flat top), non-tabular, dome, pinnacle, wedge and dry-dock (where a slot or channel has eroded into the body of the berg)
  • The largest Northern Hemisphere iceberg on record was seen in 1882 near Baffin Island. It was 8 miles (13 km) long, almost 4 miles (6km) wide and held enough water to give everyone in the world a litre of water daily for four years.
  • The Hibernia off-shore production platform, 315km away from Newfoundland, was designed to withstand the impact of an iceberg in excess of five million tonnes. It has a reinforced concrete caisson made of high-strength concrete reinforced with steel rods and pre-stressed tendons (multi-strand wires or threaded bars made from high-tensile materials), surrounded by a wall with 16 wedge-shaped concrete teeth to break up the impact of such an iceberg.
  • The Antarctic ice sheet, which actually covers a desert below it, is at least 40 million years old.
  • If that ice sheet were to melt, it would raise the world’s seas by over 60 metres (almost 200 feet) – which is one of the many reasons that global warming is so dangerous for our planet.
Non-tabular iceberg off Elephant Island in the Southern Ocean
By Andrew Shiva / Wikipedia, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=46736000

Any photos taken by me in this post may not be used without my express permission. E. Jurus