The Failed Rift

In 1811 and 1812, the city of New Madrid and its surrounding areas were caught in a series of three large earthquakes ranked as some of the most powerful in the U.S. since its settlement by Europeans. (Earthquake info from the USGS).

These earthquakes shook over 2.5 million square kilometers (1.6 million square miles). It created massive waves in the Mississippi River that covered boats, tossed others ashore, and destroyed whole islands. The ground rose and fell, bending trees until their branches intertwined and opening deep cracks in the terrain.

The most affected areas were characterized by large areas of land that were uplifted permanently, larger areas that sank and were filled with water that burst  through fissures or craters, and massive landslides that covered an area of 78,000-129,000 square kilometers.

Area affected by the earthquakes

Interesting, isn’t it? But what makes it so special? Big earthquakes happen all the time.

Earthquakes usually occur along tectonic plate boundaries, where the plates are sliding beneath, scraping past, or pulling away from each other. They can also happen near volcanoes, where increasing pressure in the magma chamber causes the earth to shake.

New Madrid, Missouri is miles away from any plate boundary or volcano. The most interesting thing near it is the Mississippi River (geologically, anyway). Basically, there shouldn’t have been an earthquake there, let alone three.

So, why did they happen?

Let’s take a dive into earth’s history. I hope that everyone is familiar with the theory of plate tectonics. A long, long time ago, the North American Plate began to tear apart. This is called ‘rifting.’ We don’t know why it did this, but it did, and it began to tear the North American continent apart.

Then, along comes another plate and shoves the North American plate back together. The rifting stops, but it left a deep wound in the continent that never fully healed.

The rift in our continent

So, in the middle of the continent is North America’s fractured backbone. In 1811 and 1812, it shifted a bit, causing the massive earthquakes.

To understand the concept better, a similar thing happened in Africa. This you should recognize – you see it every time you look at a globe. In that part of the world, the rifting wasn’t interrupted.

Do you notice how it looks as thought the Arabian Peninsula should be able to snuggle right up next to Africa? Well, it used to. That top corner of Africa rifted and tore Saudi Arabia right off.

The rift continued into eastern Africa (have you ever heard of the Great Rift Valley?) and continues to pull to this day. In a couple million years, there’ll be a new peninsula.

Here are the directions the continent is pulling:

Be grateful the rifting was stopped in North America, or it would be the Mississippi Sea instead of a river.

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The Strangest Disaster of the 20th Century, pt. 2

In the last post, we discovered that all living things withing 12 miles of Lake Nyos in Cameroon died mysteriously overnight, without any indication of cause.

And now, the conclusion. (Story taken from here).

Scientists began testing water samples taken from different depths of the lake. The murky red color turned out to be dissolved iron, normally found at the bottom of the lake. Somehow, sediment from the bottom had been churned up to the top, where the iron turned red after coming in contact with oxygen.

Scientists also found unusually high levels of CO2 dissolved in the water. As they took samples from deeper and deeper, the CO2 levels steadily increased. At 600 feet, the levels suddenly shot off the charts. Beyond that depth, the containers burst from the pressure of the gas contained within them.

The theory formed that though the volcano had long since gone extinct, the magma chamber still simmered deep below the surface of the Earth and was still released carbon dioxide into the lake and the surrounding environment.

CO2 shows up in lakes all over the world. The CO2 in Lake Nyos, however, instead of floating to the surface and evaporating into the air, was accumulating at the bottom of the lake.

Normally lakes and other water bodies convect: the surface layers cools because of rain or wind, it becomes denser than the warmer water below, sinks, and displaces the warmer, CO2 rich layers at the bottom, which then move high enough for the CO2 to bubble to the surface and disappear.

Convection example. Pretend it's a lake.

Lake Nyos is one of the stillest lakes in the world. It is surrounded by tall hills that block the wind and because it is in a tropical climate, the water temperature stays consistent throughout the whole year. Also, because the lake is so deep (690 ft), when the surface is agitated, very little disturbance reaches its depths. The unusual stillness of the lake is what made it so deadly.

There is a physical limit to the amount of CO2 water can absorb. As the bottom layers become saturated, the CO2 is pushed upward to where the pressure is low enough for it to start coming out of solution. At this point, a disturbance such as an earthquake or a landslide can cause the CO2 to bubble to the top.

These bubbles cause a “chimney” effect – basically, they create a tube through which the lake can disgorge all of the CO2 that has been accumulating at its bottom for decades.

CO2 is odorless, colorless, and non-toxic; your body produces it and you exhale some every time you breathe. The air you breathe consists of about 0.05% CO2. What makes it deadly (in some circumstances) is that it is heavier than air: if too much is released at once, it displaces the air on the ground, suffocating everything in the area. 10% CO2 in the air can be fatal – as little as 5% can smother a flame…which is why the lamps were snuffed out.

As they monitored the lake, the scientists came up with an estimate of how much CO2 was released. On August 17, eyewitnesses said the lake began bubbling strangely, causing a misty cloud to form over the surface. Then on August 22, the lake exploded; water and gas shot a couple of hundred feet into the air.

The lake ejected 1.2 cubic kilometers into the air – enough to fill 10 football stadiums – in as little as 20 seconds. (If you know anything about the 1980 eruption of Mount Saint Helens, you remember the ash that circled the planet. That was only 1/3 of one kilometer of ash – a mere quarter of the CO2 released by Lake Nyos).

Dead cattle were found as high as 300 feet above the lake, indicating the gas had reached at least that high below settling down to suffocate everything at ground level.

Some survivors said it sounded like a gunshot or an explosion; other described it as a rumble. Those who ignored it and stayed in their houses were generally safe, but those who went outside to find the source quickly died on their front doorstep. The sight of these victims brought their family members to the doors and they too passed out and were killed.

Shut doors and windows offered the most safety, but there were still cases of CO2 seeping into homes through the floors and walls and smothering those who had laid down to sleep, but those who stood with their heads above the gas survived.

Since the disaster, officials have placed a large tube in the lake to artificially create convection and channel the CO2 up into the air.

'Degassing' Lake Nyos

And thus the mystery of the strangest disaster of the 20th century was solved.

The Strangest Disaster of the 20th Century, pt. 1

I collected this story from neatorama.com, who in turn collected it (with permission) from Uncle John’s Bathroom Reader: Wonderful World of Odd.

Side note: if you do not have at least one Uncle John’s Bathroom Reader in your bathroom, you must rectify the situation ASAP.

The sun dawned on August 22, 1986 much as it did every morning previous in Cameroon. A man (unnamed) decided to take advantage of the daylight. He hopped on his bicycle and began the trip from his village, Wum, toward the village of Nyos.

On the way, he noticed an antelope lying dead along the side of the road. “Why let it go to waste?” he asked himself as he strapped it to his bicycle (somehow). He continued to Nyos, passing two dead rats, a dead dog, and other deceased animals.

He wondered if they had all been killed by lightning – when lightning strikes, it’s not uncommon for nearby animals to die of the shock. He pulled into a group of huts, planning on asking the locals if they knew anything, but as he drew closer he saw dead bodies strewn everywhere. He checked the huts – there wasn’t a living soul in sight.

The man tossed his bicycle aside and ran all the way back to Wum.

When he arrived, the survivors of whatever had decimated Nyos and the surrounding villages were staggering into Wum. With them came strange tales of an explosion, rumbling noises, strange smells, and passing out only to wake up 36 hours later and find everyone around them dead.

When medical teams arrived two days later (Wum and Nyos exist in a very remote part of Cameroon), they discovered that in the course of one night, something had killed nearly 1,800 people, in addition to more than 3,000 cattle and numberless others creature – essentially, every living thing for miles around.

And by all appearances, the killer had disappeared as suddenly as it had come.

Scientists from all over the world traveled to Cameroon to assist in the sleuthing. The remains of the victims were of little help. There were no signs of bleeding, physical trauma, or disease, and no evidence of exposure to radiation, chemical weapons, or poison gas. And none of them showed signs of suffering or “death agony.” Apparently, they all just fell over and died.

The distribution of death gave the scientists their first clue – they had all died within 12 miles of Lake Nyos. Some local tribes refer to the lake as the “bad lake.” A legend exists which says that years ago, an evil spirit had risen out of the lake and killed all the people living at the water’s edge.

The lake itself gave scientists their next big, but perplexing, clue. The water, which was normally a pure blue, had  transformed into deep, murky red. Apparently, there was more to the legend of the “bad lake” than anyone had realized.

Lake Nyos is a “crater lake” – it formed when the crater of an extinct volcano filled with water. But was the volcano really extinct? Maybe it had come back to life and released enough poison gas to kill every living thing in the area.

As compelling as that theory was, an eruption of that magnitude would have been accompanied by major seismic activity. None of the eyewitnesses mentioned earthquakes and nearest seismic recording station reporting nothing of interest happening that night.

This was backed up by the fact that in all of villages, goods were still piled neatly in homes where every living thing had been killed. The houses also offered one more interesting clue: The oil lamps had all be extinguished, even the ones still full of oil.

the newest land on earth

Tropical weather+volcano=paradise. For me, anyway.

The newest land on the planet is being generated from Kilauea Volcano on the southern coast of Hawaii. Hawaii, the state, is a chain of shield volcanoes which tend to generate lava flows a toddler could run from.

This lava flows downhill toward the coast and, over time, creates a delta, which ultimately extends the coastline of Hawaii. Thus, the new land.

From November 1986 through December 2009, the lava created 475 acres of new land. (That’s from one single eruption, by the way. 23 years).

When the lava reaches the ocean, it vaporizes the water and creates a mad plume of steam:

Kilauea plume

the birth of the Modern Prometheus

Those who have read it know that Mary Shelley’s Frankenstein is a creepy story. Scientist creates a monster who then goes on to kill all his master holds dear… Not something I’d read to my children to get them to go to sleep.

Why did this story happen? Have you guessed it?

A volcanic eruption.

Well, more or less.

From April 5-15, 1815, Mount Tambora in Indonesia went on a rampage of violent eruptions, the worst occurring on the 15th. It was estimated that there were over 82,000 deaths from Tambora. According to National Public Radio (and this website), “Mount Tambora launched 100 cubic kilometers of rock into the air – 10 times more than Italy’s Vesuvius, which buried Pompeii in 79 A.D., and 150 times more than Mount Saint Helens.”

Mount Tambora

The volcanic cloud filled up the atmosphere and dropped global temperatures by three degrees Celsius. One year later, the cloud made its way into the Northern Hemisphere and caused cooler temperature and crop failures. 1816 became known as ‘the year without a summer.’ Many areas had snow in June, and frosty nights in July, August, and September.

During this volcanic winter, 18-year-old Mary Shelley and her lover (and later husband) Percy Bysshe Shelley were visiting their friend Lord Byron in Switzerland, near Geneva Lake. The unfortunate weather conditions, thanks to Mount Tambora, were too dreary to allow for their planned summer holiday activities, so they retired to the indoors.

One stormy night, they were talking about the feasibility of turning a corpse or body parts to life (normal dinner conversation at my get-togethers, too). They were seated around a log fire in Byron’s villa, and along with discussing raising the dead, exchanged ghost stories to pass the cold night. This inspired the inspirational Lord Byron to suggest that they each write their own supernatural tale, as a sort of competition.

Later, in a waking dream, Mary Shelley conceived the idea for Frankenstein:

“I saw the pale student of unhallowed arts kneeling beside the thing he had put together. I saw the hideous phantasm of a man stretched out, and then, on the working of some powerful engine, show signs of life, and stir with an uneasy, half vital motion. Frightful must it be; for SUPREMELY frightful would be the effect of any human endeavour to mock the stupendous mechanism of the Creator of the world.”

What started out as a short story became, with her husband’s encouragement, a full-fledged novel, which we – at least I – now enjoy.

Frankenstein's Monster. Sort of.

On a side note, Lord Byron wrote a fragment based on legends he had heard while he traveled in the Balkans, and from this author John Polidori wrote The Vampyre (1819), the progenitor of the romantic (not Twilight romantic, mind you) vampire literary genre. The image of a vampire as a aristocratic gentleman first appeared in this book, and then adapted in Bram Stoker’s Dracula (1897).

Thus, two legendary horror tales blossomed from the cold shadow of Mount Tambora’s eruption.

the legend of Atlantis

The legend of Atlantis, or of a city sinking into the sea, shows up in a lot of cultures. Like…Disneyland. And Hollywood.

In a geology class I took a few years ago, I heard that it’s possible this legend rose out of a volcanic eruption.

Marvelous.

I Googled and found a number of articles on it. Here’s one.

Santorini is a circular group of islands in the southern Aegean Sea belonging to the Cyclades island chain.

Evidence shows that Santorini’s largest island, Thera, was inhabited by civilizations all the way back to the 13th century BC. In the Bronze Age, the Minoan civilization existed there with a thriving economy (unlike ours) thanks to intensive trade throughout the eastern Mediterranean. Their city on Thera, discovered beneath a thick layer of pumice, appears to have been a large and vibrant city.

Boxing boys from Thera. Civilization=sports

The whole island chain was formed by a series of volcanic events. In the late Bronze Age, however, a cataclysmic eruption (a Plinian eruption, to be exact) collapsed the central highland.

Before (probably something like this)

After

After this eruption, trade with these Minoans stopped. Solon (640-560 BC), a great sage a lawgiver from Athens, visited Egypt and was told by an Egyptian scholar about the overnight disappearance of a great island empire.

Solon’s account was written by Plato, who had received the story from a man named Critias, through his great grandfather who had received the story from Solon (and his uncle’s girlfriend’s dog’s mother…).

Quoting Critias, Plato wrote:

“Now in this island of Atlantis there was a great and wonderful empire which had rule over the whole island and several others, and over parts of the continent… But, there occurred violent earthquakes and floods, and in a single day and night of misfortune…the island of Atlantis…disappeared in the depths of the sea.”

Check out some of my personal favorite adaptations of the legend 😉 Cheers!


the anatomy of a typhoon

In the western Pacific or Indian oceans, it’s called a typhoon. In the Atlantic, it’s a hurricane. They’re the same thing, they’re just regionally named.

Hurricane/Typhoon

Now, how do they form? Tropicalweather.com explains that there are seven conditions that could cause a hurricane or typhoon to form: a pre-existing disturbance, warm ocean water, low atmospheric stability, sufficient Coriolis force, moist mid-atmosphere, and upper atmosphere divergence.

(Those are discussed in greater detail here).

The afore-linked websites are a bit wordy. So, in layman’s terms:

Tropical storms always occur in the tropics because they need ocean water of 80 degrees or higher to form. Because of the hot water, the air directly above is warm as well and as we know, hot air rises.

As this hot air rises, it leaves behind an empty space (a low pressure system) where it used to be. This void becomes a vacuum of sorts and sucks in more air, which eventually warms and rises, too.

The air cools as it rises and condenses into moisture, creating clouds. As these clouds form, and more and more air is circulated and pumped up, the system begins to spin.

(Interesting fact: in the Northern hemisphere, hurricanes rotate counterclockwise. In the Southern, they rotate clockwise).

More and more air is pumped in, warmed, and circulated throughout the system, and the storm grows in strength and size and moves across the ocean. Once it is on land, however, there is no more warm air to feed it and so it eventually dies.

Hurricanes/typhoons are rated according to their wind speed. A category 1 hurricane has wind speeds of 74-95 mph. A category five, the worst kind, has winds over 155 mph.

Hurricane Katrina