Scientific Scribbles

The voice of UniMelb Science Communication students

The Crystal Cave of Giants

Three hundred metres below the earths surface in a hot humid cavern, lies crystals as large as telephone poles, undisturbed for thousands of years.

In Naica, Mexico exists a cave that should be deemed a wonder of the world.  Discovered by two miners in 2000 on a routine check, the cave bursts with crystals of gypsum, whose size is unrivalled.  And yet, it wasn’t until 2007 that scientist realised the importance of this discovery!

Gypsum Crystal Pillars from National Geographic News

The crystals are a form of gypsum called selenite, growing from the walls of the limestone cave.  The largest crystal pillars are 11 metres long and 55 tonnes, making them as high as telephone poles and 100 times as heavy.  Gyspum rosettes continuously line the cave floor and walls; the gypsum rose I own is a mere 2 cm.

Gypsum rosettes from National Geographic News
My very own gypsum rosette

The crystal edges are sharp enough to cut bare skin, but so soft they can be scratched with a fingernail.  Simply walking on the crystals is a danger as they are slippery and prone to break.  Although they may look like icicles, these crystal are scorching hot to touch.

Why? – Being situated 300 m under the earth, places the air temperature at 40°C.  Within the cave itself, temperatures spike at 45°C.

Demonstration of cooling suits and difficult terrain. Image from Love the Whole Wide World

Explorers and scientist have a hard time viewing this natural wonder.  To an extent their lives are on the line.  This is one of the hottest places on earth humans have tried to survive!  The temperature means organs can fail and cells can die, and 100% humidity means sweat cannot evaporate and thermoregulation is impossible.  Ice suits and respirators are needed for these risk-taking individuals to even survive in the cave for half an hour.  Breathing the hot air itself can scorch throat.  The Sahara temperature meets the Amazon humidity all in one cavern the size of a football field and the height of a two story building.

Scientist however have braved this incredible and bizarre conditions, risking their lives for their work and passion.  It is thanks to their efforts, we understand how this cave came to exist.

Gypsum crystals this big need two crucial ingredients to grow: submergence in water, and heat in excess of 50°C.  Since gypsum takes a long time to grow, the cave must have been stable and under water for a prolonged period.  This is uncommon in nature, as demonstrated by the second largest gypsum crystals being only 2 m in length.  The water, heated to 58°C by an underlying magma body, was super-saturated in gypsum.  The gypsum clung to the cave walls and floor, and began growing as microscopic crystal, and then just kept growing and growing.

Prof. Stein-Erik Lauritzen collected a core sample from a large crystal for U-Th dating.  His team determined an age of an astounding 500,000 years! This means 1.5mm of increase per thousand years, for half a million years!

So why did it take so long to find? Two reasons really: depth and submergence in scalding water.  The cave is only in temporary existence.  It is only due to the lead and silver mine pumping away the water in the year 2000 that this spectacle was uncovered.  If the mine becomes unviable, then the pumps will be switched off, the cavern will flood, and all will be as it has been for the past 500,000 years.  Since it’s exposure though, the crystals have been eroding and collapsing.  As the temperature in the cavern drops year by year, so does the crystal’s stability.  So do we flood it to preserve the crystals, and loose them forever to human eyes? Or do we view and explore until it is no more?

Either way, we are still left with a strong impression of if something can be hidden from us for so long, then what other wonders is the earth and ocean concealing from our eyes?


Anja's drawing of the Naica Cave. (Couldn't resist adding this in!)

My 6-year old cousin loved watching a youtube video about this so much, she drew me a picture! That’s me in the cave by the way! And yes she even included a gypsum rose down the bottom, and no I didn’t force her to draw this, she did it of her own free will 🙂

Do Animals Mourn Their Dead?

All things considered, your first thought to that question is probably, “of course”. After all, we’ve all seen the footage of elephant herds coming across the bones of one of their own, and not only stopping their travel and appearing withdrawn, but also touching and manipulating the remains for some time before eventually moving on. There have even been some reports of elephants burying the bones they’ve come across. These are the most well known images of animals behaving in a way that would, to us, suggest they are mourning.

But scientists aren’t quite convinced. There’s not really a way to study it, after all – reports of ‘mourning’ animals are simply observations of animal behaviour, and with that comes the risk of anthropomorphising, of projecting the emotions we would feel onto the animal as it responds to death.

The question has recently been brought back to scientists’ attentions, when zoologists in Zambia witnessed a mother giraffe behaving somewhat unnaturally in response to her dead newborn. While giraffes almost never splay their legs to bend down (unless feeding or drinking), and although females rarely spend time alone, this mother did both, spending two hours away from other herd members, investigating and licking her dead calf.

Giraffe Family © user Flowtastic, licensed under Creative Commons

This is only the third incidence researchers have found of a giraffe seriously investigating its dead, but it does raise the question of whether these animals are also capable of grieving. In another example, a dam in Kenya in 2010 spent four days by the side of her dead one-month-old calf. Another 17 females were seen surrounding the body at different times during these four days.

And it’s not just mothers that appear to be mourning the loss of family members. Jane Goodall in her book Through a Window, discussed the event of a young male chimp who, a few days after the death of his mother, grew lethargic and stopped eating, before a weakening of his immune system made him sick. She reported his last journey was back to the same place his mother had died, where he spent hours staring and motionless, before he moved on a little further to lie down, curl up, and simply never move again. To most of us, this is a clear indication of heartbreak and utter grief.

Zoologists are not quite convinced. It would certainly take a great deal of study involving many species, and many different relationships between animals. It could be, even, that there is an evolutionary benefit behind mourning. Shared grief could help reinforce bonds in a social group during a time when those bonds are weakened. It may also help re-establish a hierarchy after the loss of a valuable member.

Images of animals we believe to be mourning do resonate with us, but whether that is simply our sympathy projecting into our perceptions, or whether it is actually because we’re witnessing an animal undergoing emotional suffering, for now just remains to be seen.

If you’re interested, you can find Jane Goodall’s book here.

Also, see the BBC  Nature article from which information for this post comes.

Successful Tesla Museum Funding Electrifies The Internet

Popular webcomic The Oatmeal has launched a campaign to raise enough money to buy land which previously held Nikola Tesla’s old laboratory, Wardenclyffe, and to convert it into a modern day museum of his work. The project has received strong support, and has passed their target funding necessary to make the project a success, reaching 1 million dollars in funding in the first 9 days of the campaign.

Nikola Tesla was a true scientist and renaissance man, who among his achievements assisted in developing alternating current, which allows the transmission of higher voltages over longer distances. He also came up with a very basic description of a radar, performed early experiments with x-rays and conducted famous experiments and demonstrations of wireless energy transfer. His works would certainly provide plenty of material for an amazing science museum.

I highly recommend a look at the oatmeal’s page on the plans for the tesla museum, as well as reading about his other achievements and scientific prowess, aggressively argued in this oatmeal comic.

One small step

I woke up about an hour ago to see in the newspaper that Neil Armstrong had passed away. He was 82 years old.

The moon landing was 20 years before my time, but I, like any kid since then, grew up knowing about Mr. Armstrong. I never knew him personally, of course, but from what I can glean from reports of those nearest and dearest to him, he was a kind and humble man who used his considerable public presence for philanthropy rather than ever “cashing in”.

This is not going to be a long post. I’m sure someone else will be far more knowledgeable about Neil Armstrong and Apollo 11 than me, and that person will blog about the wonderful history of the space race and moon landing.

I just wanted to say a short goodbye to a man who inspired scientists and non-scientists alike to defy expectations and explore the world beyond the limits we know. His legacy has lasted for more than 40 years already, and I think it will live on forever.

In the closing lines of the statement released by his family, they asked this:

For those who may ask what they can do to honor Neil, we have a simple request. Honor his example of service, accomplishment and modesty, and the next time you walk outside on a clear night and see the moon smiling down at you, think of Neil Armstrong and give him a wink.

I, for one, plan to give the moon a wink tonight, and I think all of us as scientists should endeavour to honour the example of this self-described ‘nerd’ in our pursuit of knowledge.

RIP Neil Armstrong. You were fantastic.

Neil Armstrong on Apollo 11, 1969

Image licensed under creative commons

Exploding Lakes

Lake Kivu, Lake Monoun, and Lake Nyos might sound just like any other ordinary lakes but they are actually three of the most dangerous lakes in the world. Situated in the boarder of Rwanda and Democratic Republic of Congo and Cameroon in South Africa, the latter two, have caused some of the worst natural disasters in the 1980’s. These events killed almost 1900 people, 3500 livestock, and many wildlife in the surrounding villages and towns.

Carbon dioxide resulting from the close association with volcanic activities is the reason why the lakes are so deadly.

Imagine a fizzy drink bottle being as big as 132 million m3. It contains A LOT of gas and is under a lot of pressure. This is what it’s like deep down at the bottom of the lakes. The water is saturated with dissolved gas –carbon dioxide. The high pressure exerted by water at great depths keeps all the gases inside. As pressure increases, more gas is dissolved in the lake. However, if the pressure was removed, all the gases will start bubbling out.

Diet coke explosion  (source wikimedia commons)

That is a disaster and not just any ordinary disaster, it is a limnic eruption. Limnic eruption is a rare natural phenomenon, where a large amount of carbon dioxide gas is released from a deep lake, also known as lake overturn.

The limnic eruptions in Lake Monoun and Lake Nyos were resulted from landslides and phreatic explosions respectively. The eruptions caused large clouds of carbon dioxide to be released above the lake and expanded into the surroundings. Since carbon dioxide is heavier than air, it can displace oxygen and fill the area with unbreathable air. Consequently, people and animals died from carbon dioxide poisoning and severe oxygen deficiency called asphyxiation.

The picture below describes what happened in Lake Nyos in the 1986 limnic eruptions.

Source Frimmbits

Lake Kivu differs from the other exploding lakes and contains large amount of methane in its water column – 55 billion m3 and still increasing. Methane is highly explosive and could trigger further release of carbon dioxide once ignited. Scientists suspected that Lake Kivu could contain 1000 times more gas than Lake Nyos and Lake Monoun. Hence, the consequences of limnic eruptions in Lake Kivu could be catastrophic and especially dangerous to the two million people living around the lake.

Another lethal outcome of limnic eruption is the occurrence of tsunami caused by the displacement of water in the lake due to the escaping gas. The tsunami wave in the 1986 limnic eruptions in Lake Nyos was recorded to reach 20 metres in height.

At the moment,  in order to prevent further disastrous events, a pipe has been inserted into Lake Nyos . The carbon dioxide at the bottom of the lake is slowly released via the pipe, which reduces the build-up of gases in the lake.  Similar project has been suggested to implement at Lake Kivu called KivuWatt. However, instead of carbon dioxide, the methane is extracted as an energy source to provide electricity to the people living near the lake.

Here is a youtube clip of dry ice bubbles which resembles the build-up of carbon dioxide in the lake and exploded. Note that all the gas escaped and sank to the bottom, which was how the gas expanded to the nearby villages and towns in the 1980’s limnic eruptions.

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