Saturday, May 4, 2013

Welcome to Hell

These jagged pillars and pinnacles protruding from Grand Cayman’s tropical landscape are actually the result of limestone attacking filamentous algae reacting with inshore limestone formations. “Phytokarst” is the scientific term used to describe these land formations that occur sporadically in places across the world such as Malaysia, Ireland, and pictured here, Grand Cayman.

The algae filaments bore their way into the limestone and in turn create this black organic coating that protects them and their host rocks from sunlight and other natural elements. Surprising it is, to think that most of this landscape was once white limestone before it became consumed by the algae. The algae have such a strong influence on the limestone that they actually dissolve much of the stone in their effort to protect themselves, obtain metabolic carbon, or obtain a damper tunnel environment for which they can better hold capillary water. Phytokarst environments are believed to exist mostly in places with high humidity and tropical climates, such as Grand Cayman, though they are also known to exist in caves and other limestone-rich environments.

So, you can go to Hell… At least if you want to see an interesting relationship between tiny algae filaments and natural limestone. Quite cautious they are in Hell, protecting visitors from the sharp and edgy phytokarst limestone, only letting them view the pinnacles from a safe distance. On your way out, be sure to stop by the Visitor’s Office and pick up a few postcards for friends and relatives, proving that you have been to Hell and back.

Photo Credit:
Wikimedia Commons


Is the Earth smoother than a billiard ball??

You may have heard at some stage that “If the Earth was shrunk down to the size of a billiard ball, it would actually be smoother”. If you haven’t heard it before, well, welcome to the group!

Billiard balls are pretty darn smooth and according to the World Pool-Billiard Association have a tolerance of +/- 0.0127 cm. Essentially, this means that a ball must not have any bumps or indentations greater than 0.127mm- which is about the width of a strand of hair.

If we find the ratio of the diameter of the ball (6.35cm) and the size of the allowable surface coarseness (.0127cm) we get a ratio of around .002 (.0127/6.35). So, this means for the Earth to be deemed as smooth as a billiard ball it’s diameter to tolerance ratio must be equal to or less than .002.

So.. is it?? *drum roll*

The average diameter of the Earth is around 12,742 km. If we use the ratio from above we can find out what the allowable “tolerance” would be to achieve billiard ball smoothness, as follows: 12,742 x .002= 25.482km.

Essentially, this means that we have over 25km to play with regard deviations in topography- so let’s take a look at the highest and lowest points on the planet:

The highest point on land is the peak of Mount Everest at 8.84 Km above sea level- well within the 25km range. (Or, if you want to get technical, the highest point on the Earth is Mt. Chimborazo in Ecuador in the Andes mountain chain. It’s about 2.4 kilometers higher than Mt. Everest due to the Earth being an oblate spheroid and bulging around the equator, but is still less than than 25km)

The lowest point is the Mariana Trench at around 11.03 Km below sea level- also within the 25km range.

So, there you have it. If you could shrink the Earth down to the size of a billiard ball it would actually be smoother!!

-- @chaowlah


The growth of vegetation in Arctic climatic regions may begin to resemble that of more temperate and tropical regions. Researchers from NASA and Boston University conducted a 30-year study based firmly on satellite information to make this assertion.

The scientists used satellite data to determine changes in plant growth over the years they have studied. The satellites in use from NASA, which contained NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instruments, also held NOAA's Advanced Very High Resolution Radiometers (AVHRR); these devices provided the high-resolution information used to determine their study results.

The study, published in the March issue of Nature Climate Change, examined the relationship between temperature change and plant growth spanning from 45 degrees north latitude to the Arctic Ocean. According to the study, increased temperatures have warmed the atmosphere, which in turn melts ice found in northern latitudes. As the ice melts, the ground becomes exposed, further warming the atmosphere and causing plant growth. The scientists define two main study areas where this is occurring: the boreal vegetated region (45-65 degrees N latitude) and the Arctic (areas north of 65 degrees N latitude). According to the study, in those areas between the latitudes of 50 degrees N and 75 degrees N, there has been a measured increase in temperature of 1 to 2 degrees Celsius between the early 1980s and the late 2000s, when there was also a smaller difference between summer and winter temperatures recorded. During this time, the amount of vegetation in this region increased so that it is similar to vegetative covering on lands 4 to 6 degrees farther south. The area of landscape that is now productive in these northern regions is equal to the size of the contiguous United States.

As a result of this vegetative change brought on by warming, the study predicts other outcomes, including thawing of ice in mid-winter, droughts, increased fire and pest outbreaks, and shrinking ponds. Some of these effects may actually slow the growth of vegetation, which could stop this cycle from continuing. In addition, the warming temperatures do not always cause plant growth in that water and sunlight are also necessary for the growth of vegetation. Those areas studied that were warmer and wetter measured more plant growth than those that were warmer and drier.

Photo credit: Terry Callaghan, EU-Interact/Sergey Kirpotin, Tomsk State University. The picture depicts melting permafrost and increased vegetative growth near the Altai Mountains in Russia.


“Parting” of the Jindo Sea

Here’s a story about a lady and a tiger. According to a Korean legend, tigers were once abundant on the island of Jindo in the Jindo Sea, just off the southwest corner of the Korean peninsula. Tigers began to invade villages on the island, so the people fled to neighboring Modo island. Unfortunately, a woman named Bbyong was left behind. She prayed to the ocean god daily and was finally told in a dream that a rainbow would appear in the sea the next day to let her cross to her family. When she walked out to the shore the next day, a rainbow road magically appeared, and Bbyong’s family crossed the sea on the road to finally meet up with her again. The event is celebrated every year during the Jindo Yeongdeung Festival, or Sea-Parting Festival.

The traditional story has its roots in a completely natural phenomenon that occurs every year around this time. The Jindo-Modo land bridge appears twice a year, in May and June when very low tides expose a 2.9 kilometer land bridge between the islands of Jindo and Modo. The land bridge appears for a little over an hour, allowing tourists and residents to walk across the sea from one island to the other.

The land bridge is not a miracle. It is a result of tidal harmonics. Tides are the rise and fall of sea levels caused by the gravity of the sun and moon pulling on the ocean surface. The sun and moon pull at the earth with different strengths at different times, depending on their relative positions. The earth’s rotation, shape and size of ocean basins, and local coastlines affect the magnitude and frequency of tides. Each of the contributions to the tides can be broken down into simpler components, or waves. The phase and size of each wave is unique to each location. Occasionally, these waves can line up in the same phase and create an extremely high or low tide. This is the case with the Jindo-Modo land bridge, when tidal harmonics line up to produce an extremely low tide in May and June, exposing a ridge of sediment between the two islands.

The exact date of the Jindo Sea land bridge crossing changes each year. Although the land bridge appears 2-3 times in the spring, the festival is celebrated only once.


Point Dume, California

As one follows Highway 1 north and west of the city of Los Angeles, the highway and the Pacific Coastline that it follows turns almost due west and becomes a remarkably pleasant drive through the community of Malibu, California; home of some of the most expensive real estate in the country.

Coastlines usually have lots of inlets, bays, rivers, etc., things that disrupt straight lines on the map, but that’s not the case in this area. Much of Malibu is sandwiched between the coastline and a set of hills to the north. Of course, if there are hills in the area, that probably means there’s a fault.

The Malibu Coast Fault is a thrust fault that sits right along the coastline in Malibu, running for about 30 kilometers almost due east-west. This fault dips to the north; the rocks to the north are being pushed up over the rocks to the south. To the north, there sits an east-west striking mountain range uplifted by this fault, the Malibu Hills, which transitions smoothly into the Santa Monica Mountains and the Hollywood Hills closer to the L.A. basin

This photo is of the one feature in Malibu that isn’t like the other. This spot, known as Point Dume, is the one spot in Malibu where the land juts out into the sea. It’s readily visible on maps and satellite photos; it sticks out several kilometers into the ocean, with flat terraces on the top.

Point Dume is a location where the Malibu Coast Fault has broken into several sections, called “splays”. To the east and west, those strands join back together to form a single fault, but here, there is land trapped in the middle of multiple fault segments. The trace of one fault strand can actually be seen in this image; look closely at the rocks on the point. Just above the wave line, there is a color change between dark rocks at the base and lighter brown rocks above. That color change marks one strand of the Malibu Coast Fault.

The presence of this fault means that the entire area sits under a seismic threat. This system is comparable to the one on which the 1994 Northridge earthquake happened; a thrust fault associated with the formation of the L.A. Basin and the mountains around it, so large, damaging earthquakes are possible. Yet, given its location and climate, it is clearly in high-demand for real estate and recreation.

If there wasn’t a state park to protect it, and you didn’t know about the fault, Point Dume might seem like a great place to put a house. Imagine the house you could build there; big glass windows overlooking the Pacific Ocean on every side.

Of course, that kind of house isn’t hard to imagine. In fact, if you go to a movie theater this weekend, I believe you get to see that very house crash into the ocean. Point Dume is the site of Tony Stark’s house in the Marvel Movie Universe. (I promised another Iron Man 3 post, here it is).

Point Dume has served as the location for other Hollywood filming, including the penultimate scene in “Planet of the Apes”. The beach to the left of this image was used, with a matte painting employed to replace the rocks with the Statue of Liberty. But for this weekend, this is Stark’s mansion.

There isn’t really a house on Point Dume, obviously. It’s a state park, so the land itself is moderately protected and available for public use. The house in the movies is completely done on sound stages and computers. And frankly, that might well be a good thing; I don’t think you could convince me to build a house sitting tens of meters above the Malibu Coast Fault. But, if you’re going to be a multi-billionaire industrialist superhero, and you want a great view…seems like Point Dume is a good choice. Anyway, that’s it for me writing for today, I’ve got a movie to go see.

Photo Credit (Nonprofit use): Bruce Perry, Department of Geological Sciences, CSU Long Beach

Malibu Coast Fault:

LA Basin fault maps:

1990 Article on Malibu Coast Fault activity:

Tony Stark’s house, Marvel Universe Wiki:


The Environmental Protection Agency (EPA) has declared this week to be Air Quality Awareness Week. During this time, we are supposed to learn about how atmospheric pollutants can affect our health. A recent study highlights the importance of this knowledge. Humans exposed to high levels of air pollution may experience health problems other than those affecting the lungs. Scientists at the University of Michigan and the University of Washington found that exposure to high levels of toxins in air may link to more rapid atherosclerosis, which potentially could result in heart attacks and strokes.

Atherosclerosis results when fat, cholesterol, and calcium deposits, all referred to as plaque, accumulate inside the arteries. Arteries are vital in that they carry oxygen-rich blood throughout the body. As these deposits build in the arteries, the supply of this blood is diminished, and can cause heart attacks, strokes, or death.

Particulate matter may be one of the contributing factors to these detrimental health effects. This substance is released from the burning of gasoline and from the combustion of fuels within power plants. The researchers discovered that the presence of fine particulate matter (PM2.5) was linked to the buildup of plaque within the inner two layers of the common carotid artery. The carotid artery supplies blood to the front portion of the brain, as well as the head, neck, face, and spinal cord. In contrast, the researchers also found that lower levels of particulate matter were associated with a slower thickening of the arteries.

In order to find these results, the researchers obtained data from the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), which followed 5362 people between the ages of 45 and 84 without known heart problems in order to find a link between air pollution and cardiovascular disease. MESA Air is a ten-year study and is funded by the EPA.

The scientists adjusted for personal factors such as smoking. The people examined in the study live in six major metropolitan areas in the United States. MESA Air has set up data collection with fixed site pollution monitoring equipment, air samplers, home outdoor and indoor monitoring equipment, and from personal sampling. Air pollution levels were measured at each person’s house and were matched with two ultrasound measurements of the blood vessels. Each reading was separated by a three-year gap. Those exposed to higher levels of particulate matter within the same city experienced faster plaque buildup, potentially increasing the risk for strokes and heart attacks. There are limitations to this study, however, including outside factors other than particulate matter that may be linked to the plaque buildup.

Despite its potential limitations, this study highlights the need for strong environmental legislation due to its significance in predicting long-term harmful human health effects.

Photo of Beijing smog courtesy of Bobak Ha'Eri via Wikimedia Commons.


For your consideration…the Alabama Hills

Ok, I’ll be honest …I’m secretly hoping someone screams “Nerd!” at me in the comments, because in this post I’m reveling in it. I’ve already got my tickets for Iron Man 3 this weekend, and considering that Disney is spending tens of millions of dollars marketing that film, I might as well try to tag along. Either I’ll be stealing attention from their marketing, or helping it, or maybe both. So, for this post (and my next one), I’m delving into geology that appeared in the first Iron Man film.

This image comes from the state of California, just outside of the town of Lone Pine, a place known as the Alabama Hills. In the background, you can see the Sierra Nevada mountain range, with Mount Whitney, the highest peak in the continental United States, in the distance almost at the center of the frame.

In California, the main mountain range, the Sierra Nevada, runs north-south through the state. On the west side, the Sierras gradually lose elevation and merge into sedimentary basins in the Central Valley, but on the east side, they stop abruptly.

The Sierras are cut on their eastern side by a series of normal faults that have dropped the rocks down and created a deep, sediment-filled basin known as Owens valley. You can see the trace of one of those faults in this image; it basically marks the place where the mountains go from incredibly steep to very flat.

The Alabama Hills sit right in the middle of Owens Valley. They’re made of granite that is very similar to the rocks of the Sierra Nevada, but there are about 3 kilometers of valley floor between them and the Sierras. The Alabama Hills are a block of the Sierras basically trapped in the middle of Owens valley.

These hills are pieces of Sierran granite, but because they are bounded by faults, they didn’t drop down as far as the rest of the valley. The faults around the hills still move, and in fact there was a magnitude 7.4 earthquake along the east side of the Alabama Hills in 1872.

They sit in an incredibly picturesque area. There isn’t a lot of rain, so the hills don’t erode rapidly, but since they’re not big they’re easy to climb on or drive around, and they have the gorgeous Sierra Nevada as a backdrop. These hills are such a great location that they show up throughout Hollywood history. The other name for the portion of land right around the Alabama Hills sums this up pretty well; Movie Flat. If you look in the background of any number of “western” movies, there’s this remarkable habit of Mount Whitney showing up. Django Unchained, Gladiator, Tremors, How the West was Won; the list of films shot here seems endless. Captain Kirk was even buried here.

The Alabama Hills also sit in the rain shadow of the Sierras; they don’t receive much precipitation, making the area great for filming desert scenes. The weathering granite helps as well, it weathers to grus; broken up fragments of the grains in the granite that don’t host much vegetation and give a good impression of a desert when they’re on camera.

That brings me back to Iron Man. In the 2008 Iron Man film, the Alabama Hills played a key role, standing in for Afghanistan. This spot is where Tony Stark demonstrates the Jericho Missile. In fact, they test the missile on the Sierras; literally on the slopes just south of Mount Whitney. The scene where Stark is attacked and captured by militants, leading to the development of his miniaturized arc reactor, was also filmed right here, in the Alabama Hills. So effectively, the entire Iron Man film series (and the other Avengers movies) got their start right here, in the shadows of Mount Whitney.

So, to paraphrase the movie…ladies and gentlemen, for your consideration…the Alabama Hills.

Photo credit: Me! No rights reserved.

1872 Lone Pine Earthquake:

Alabama Hills on Tripadvisor:

Alabama Hills from the BLM:

Lone Pine Film Database (39 pages!):

And why not, the video clip:

Toxic Berkeley pit

Presently known as one of the most toxic man-made lakes on earth, the Berkeley pit in Butte, Montana used to be one of the largest open pit copper mines. Several underground mines were combined to form the open pit in 1955 by Anaconda Copper (the company also owned the largest copper smelter in the world in the nearby town of Anaconda). Imagine that under the city of Butte around 78 km of vertical and 9000!! km of horizontal underground shafts are located. (See: These mines produced not only 9.6 million tons of copper, but also 2.1 million tons of lead, 22,000 tons of silver and 90 tons of gold between 1880 and 2006. Since Butte lies in the headwaters of the Clark Fork River, the groundwater level had to be lowered as the... underground mining went deeper.

The open-pit mine was in operation until 1982 when the dewatering pumps were turned off and the pit filled with water. Well, you can almost not call it water since it is so saturated with copper that miners are able to mine copper directly from the water. The acidic water does not only contain high concentrations of copper but also sulfuric acid, iron, cadmium, arsenic and zinc. With a pH between 2.5-3.0 it is as acidic as vinegar. If you would drink a bottle of the water it would form a corrosion layer in your digestive system meaning basically that you die of rust.

The pit is 540m deep and filled with acidic water to a depth of 270 meters. It is thus remarkable that bacteria, fungi and algae manage to survive in the lake. More than 100 types of microbes were discovered in the lake by Don and Andrea Stierle. It is natural selection at its height, since some of these organisms are solely found in the lake.

A flock of 345 snow geese landed in the lake in 1995 and died. The custodian of the pit first denied this was due to the toxicity of the lake and claimed it was due to a ‘grain infection’. However, the state of Montana revealed that the insides of the geese were filled with burns and sores caused by high concentrations of arsenic, copper and cadmium. Nowadays gunshots and loud speakers are supposed to keep the birds away from the lake.

In 2003 a water treatment plant was built near the northeast rim of the pit to prevent water levels from rising and contaminating the groundwater. Drinkwater is being pumped from high land reservoirs, since historic mining has already contaminated the valley aquifer. For now the Berkeley pit remains the only toxic lake in the world you have to pay (2 dollars) to visit.

Image: Courtesy of Barbara Oosterwijk. The Berkeley pit as seen from the viewing platform. If you look close you can see the reddish color of the water.


Dobb, E. 2000. New life in a death trap. Discover

Natural Disaster: Cyclone Nargis

Today marks the anniversary of a recent natural disaster of huge proportions. Cyclone Nargis hit the country of Myanmar (Burma) on May 2, 2008, leaving at least 138,000 people dead and causing over $10 billion US dollars in damage. The UN estimates over 2.4 million people were severely affected by the storm. It was the worst natural disaster in the recorded history of the country, and the second deadliest named cyclone of all time, behind Typhoon Nina in 1975.

Nargis was the first named tropical cyclone of the North Indian Ocean cyclone season. It developed on April 27, 2008 in the Bay of Bengal and quickly strengthened. By landfall on May 2, the Joint Typhoon Warning Center estimated peak winds of at least 215 km/hr (135 mph), equivalent to a weak category 4 storm on the Saffir-Simpson Hurricane scale.

The storm took the worst track possible as it turned sharply eastward and headed toward the low lying areas of Myanmar, rather than the more mountainous areas to the north. The great death toll from the storm was largely the result of a storm surge of at least 3.6 meters (12 ft.) that moved 40 km up the highly populated low-lying Irrawaddy river delta. Much of the protective vegetation of the delta had been cleared to make room for rice paddies and shrimp farms, making the area more vulnerable to intense storm surges. It was Asia's Hurricane Katrina, but with even deadlier consequences.

Since the storm, research scientist Bo-wen Shen has been working with NASA and the Pleiades supercomputer to try to simulate the Cyclone Nargis using the latest computer models. He has been able to replicate the formation of the cyclone five days in advance, giving some hope that future storms can be predicted early enough to try to move people out of harm's way. However, moving millions of people from the path of a storm even days in advance is not an easy task.


Image of Cyclone Nargis on May 1, 2008 courtesy of NASA

The Tara sails again

Like a modern day Fram, the Tara will set sail from the French port of Lorient on another Arctic expedition on May 19th. A 36 metre, two masted schooner built in 1989, it is owned by the environmental NGO Tara expeditions, and has been involved in oceanographic work since 2004. It was owned by two explorers before Tara, the second being tragically murdered while sailing the vessel up the Amazon. Built to withstand extreme conditions, it re-created the epic journey of Nansen's Fram in 2006, drifting for 507 days between Russia and Greenland while encased in sea ice, accomplishing the journey in half the time of Nansen's 1894-6 expedition. During this time they helped quantify the environment and loss of the Arctic ice cap during international polar year.

Tara Expeditions are a French NGO, working to trace the effects of climate change in the world's oceans. The primary objective of this expedition is to complete its Tara Oceans project (2009-12), sampling plankton and correlating them to ocean chemistry and temperature in all the world's oceans. This has helped establish a global baseline from which to assess the rapid changes occurring in a warming world. Adaptation to the current changed conditions is also studied. This has been compared to taking the planet's biological pulse, since plankton react quickly to environmental changes, and are extensively used to monitor past climate changes. Knowing what we have today is the first step to understanding change tomorrow.

The Arctic is the one ocean yet unsampled, and the place where the most warming and associated changes has occurred. A complete transformation of the ecosystem is already under way, and rich fishing grounds depend on the plankton in the water, so an examination of the ecosystem is urgent. As food scarcity increases due to climate change, overfishing and other reasons, the Arctic is hoped be the next fishing bonanza. With the increasing loss of summer sea ice, under which the base of the marine food chain often live, both the ecosystem and fishing grounds are under threat.

The plan for the Polar Circle Expedition is to circumnambulate the ocean via both the Northeast and Northwest Passages during the summer months, returning to Lorient in November after a 25000 Km journey. The research team consists of 15 scientists, since the vessel is small. Further research into mercury and plastic particle pollution is also on the menu. Research suggests mercury is concentrating at the poles, and an ocean wide quantification would make another very useful baseline.

We wish them luck in their important work. It all goes to show that you don't need a ship the size of the IODP's Joides Resolution (see past post at to accomplish world class research.

Image credit: Timo Palo.

Press release:

Caño Cristales, Colombia

Dubbed by many "The Most Beautiful River in the World", this waterway's stunning appearance arrives for a brief moment every year between the rainy and dry seasons. The bright colors seen are the various tints of aqueous plant life and algae in the water. They are produced when they receive the perfect combination of water level and sunlight.

Located in the jungles near the Colombian city of Macarena, the riverbed of this natural wonder is covered in numerous layers of moss, coral, aqueous plants, and Macarenia Clavigera, a rare endemic plant native to this geographical location. It is of red color, hence the overwhelming shade seen in the abundance of pictures of Colombia's Caño Cristales.

For all of the rock lovers out there, let's talk petrology! The rocks of the riverbed and surrounding area are approximately 1.2 billion years old, and are thought to be an extension of the Guiana Shield in Northeast South America. The water is both sediment and mineral rich, and allows for a wide variety of aqueous plant life. The course of the river over time has also formed a number of deep water pits, referred to as "Giant's Kettles".

Although red is the dominant color seen in the river, the various forms of plant life and coral form a wide spectrum of colors, giving the river an additional nickname, "the river of seven colors".

Today, the river is a popular tourist attraction, but it had been closed for several years due to guerrilla activities in this Colombian region. However, it has since reopened and remains a protected international treasure today.

Image Credit: Discover the Trip


Rockall, the UK’s largest mountain?

A tiny pinnacle rising from the turbulent sea about 300 kilometer from the nearest land. Rockall is known as one of the smallest islets in the world, but is actually a pretty large mountain rising to 2000m, of which only the 21m high tip comes out of the ocean. Often the islet appears from the sea mist and waves crash over it making it pretty much inaccessible. Well, save for some seabirds that have given the top of Rockall its distinct (bird-shit) white color. In 2000 individual waves of 29m high were measured, the highest waves ever recorded by scientific instruments in the open ocean.

Rockall is part of the Rockall Plateau, a 800 by 150 km fragment of the continental plate or a micro continent formed 300-270 million years ago when the supercontinent of Pangaea began to break apart. The pinnacle of Rockall islet is an eroded remnant of volcano most likely dating to 60-50 million years ago when North America and Greenland finally split from Europe. This period was characterized by extensive volcanic activity. The volcano was last active 55 million years ago. After the period of volcanism the plateau began to lower. The 3000m deep Rockall Though (a deepwater geological feature) separates the Plateau from the British Isles. A map of the underwater mountain ranges of Rockall plateau can be viewed here:

Remarkably, geological features on the Rockall plateau are officially named after the geographic features of Middle Earth from Tolkien’s Lord of the Rings, for example the Edoras, Fangorn and Lorien banks, the Rohan and Gondor Seamounds and the Isengard Ridge.

In 1975 a new mineral called bazirite was found at Rockall which is chemically composed of barium and zirconium. Besides this Rockall is made up from peralkaline granite. Two km northeast of Rockall lies Helen’s Reef, a series of skerries which only submerge from the water sporadically. A skerry is considered a rocky island too small for habitation. As you can see there is a void in between the definition of a skerry and an islet (a very small island which is also too small for habitation).

Image: Rockall with a fishers boat and a whale in the left corner of the image.

British Geological Survey:

Sutherland D.S. 1982 Igneous rocks of the British Isles.

Holliday, N et al. 2006. Were extreme waves in the Rockall Trough the largest ever recorded? Geophysical Research Letters 33:5

CHERT / LIMESTONE: The Oil and Vinegar of the Rock World

Just like the dressing on your salad, the silica of chert and carbonate of limestone don’t mix.
Within the oceans, plankton either have shells of carbonate material (more commonly aragonite today but more commonly calcite in the Cretaceous) or silica (that is, the material quartz is made of). In rough approximations, generally there are just a few percent of siliceous-bodied plankton among the much higher population of carbonate-bodied plankton. When the plankton die and their remains slowly settle onto the bottom of the more shallow seas, they accumulate as fine-grained sands, layers upon layers of fine-grained sands, meters and tens of meters and hundreds of meters of fine-grained sands that eventually are sufficiently buried to a depth where they become rocks.

While they are becoming rocks, a process known as diagenesis, the unmixing magic occurs: aragonite’s structure changes to that of its more stable pseudomorph calcite. And all those miniscule calcite grains begin to merge to larger calcite grains, crystal lattices growing growing growing within the rock, become a proper limestone.

And then, there’s the silica grains mixed with the carbonates. In common ocean conditions, these were well mixed with the carbonates, but now that the carbonates are recrystallizing all over the place, what’s a poor silica molecule to do? It doesn’t bond with the calcite structure, so… it becomes an outcast, pushed away from the expanding calcite minerals, expelled to layer contacts, fractures and voids within the hardening sands and even into the dissolving remains of larger sea creatures.

When enough silica material is expunged from the carbonate host, it also joins together in forming rocks of its own, chert nodules consisting of horrendously fine-grained silica. These silica deposits can then be found in layers or, more easily recognized, as spherical concretions within the limestone. Flint is one variety of cryptocrystalline quartz formed in this way: when the silica crystallizes with water in its molecular framework, it can form opal.

Chert and flint nodules within limestone are among the most common kinds or rocks used by our stone age ancestors in making tools. They are so homogeneous in make-up that they don’t split up along fracture planes or break into unwanted awkward shapes. They are so fine grained as to have a glassy-kind of cleavage when broken (like in the broken glass of a pop bottle) so they can make durable sharp cutting edges. So, it’s not surprising that any rock formation of limestone that contains chert nodules is also a good place to start looking for the tools and chips made by our early ancestors.

Stone Age tool makers did not understand about the geology of diagenesis: but they did use its products to find the right rocks to make their axes and knives.

Photo from Vikos Gorge by Dina Ghikas; Neolithic tool added by me from my photo collection.

Going to the Sun?

Glacier National Park in northern Montana in the US covers over 4000 square kilometers and is filled with over 130 lakes, 12 active glaciers, and hundreds of species of plants and animals. However, It is probably most well-known for one particular road that winds through through the park, Going-to-the-Sun Road.

Going-to-the-Sun Road is the only road that crosses the park, passing over the Continental Divide and Logan Pass at 1,965 meters (6,446 ft) elevation. The narrow and winding two-lane road is steep with few guardrails due to numerous avalanches in the winter months. It is considered one of the most difficult roads to plow in North America. The road is only open for 2 to 3 months in the summer, but the views of glaciers, waterfalls, and mountains along the scenic drive are well worth the wait.

Construction of the road began in 1921 as one of the first National Park Service road projects specifically for automobiles. It was not completed until late 1932, at a cost of $2.5 million. In 1985, Going-to-the-Sun Road was dedicated as a National Historic Civil Engineering Landmark. If you can't make the trip in person, you can check out the Glacier National Park photo page, which is filled with images taken throughout the park.


For a past Earth Story post on Glacier National Park, see:

Image of St. Mary's Lake and Wild Goose Island from Going-to-the-Sun Road, credit Ken Thomas

Wednesday, May 1, 2013


In the mountains within tropical and subtropical latitudes, persistent clouds develop, creating what is called a cloud forest, or bosque nuboso in Spanish. Within Costa Rica lies the Monteverde Cloud Forest, where sunlight is often blocked from entering by thick cloud cover. As a result, very little evaporation occurs. The presence of this abundant water allows for an incredible amount of biodiversity. Approximately 2.5% of the world’s biodiversity is found in this location.

Within the Monteverde Cloud Forest is the Monteverde Cloud Forest Reserve, which encompasses over 14,200 hectares of land. Within this preserve are over 100 species of mammals, 400 bird species, 1,200 reptile and amphibian species, and numerous insect species, including 500 types of butterflies. Many of these species are endangered and endemic, which means they can only be found in this area of the world. The Santa Elena Cloud Forest Reserve is also within the forest, and also has many diverse species represented, including spider monkeys.

Visiting this location also affords another unique opportunity besides the exploration of many plant and animal species. The Monteverde Cloud Forest Reserve is on both sides of the Continental Divide in Costa Rica, so you can stand on both the Caribbean and Pacific sides of the slope. A continental divide separates major streams that will not join each other before they enter another river or sea, and separates surface waters that will eventually flow into different oceans.

Despite its high biodiversity, this region is very vulnerable to change. The golden toad, endemic to Monteverde and last seen in 1989, is thought to have gone extinct due to El Niño or anthropogenic climate variations that led to a drying effect on the forest. The incredible and unique species in this area must be viewed with care, as they exist in a delicate balance.

Photo of a canopy walkway near Santa Elena, Costa Rica courtesy of Dirk van der Made via Wikimedia Commons.



Trees may produce compounds that may harm human health and contribute to the presence of atmospheric air pollution, according to findings from researchers at the University of North Carolina at Chapel Hill. The study was published in this month’s Proceedings of the National Academy of Sciences.

Certain tree species, such as oaks, poplars, and eucalyptus, produce a compound called isoprene. The production of isoprene allows plant leaves to be better adapted to rapid heating from the sun, and can help them tolerate certain airborne compounds, such as ozone. This adaptation has shown to be contributing to the production of certain harmful air pollutants, however. Isoprene can react with hydroxyl radicals in the atmosphere to form the pollutant ozone. Inhalation of ozone can cause lung problems, such as coughing, tightness, pain, and burning of the chest, shortness of breath, and throat irritation. Isoprene can further react with this produced ozone to produce more smog particles, which can exacerbate lung problems such as asthma.

The researchers have also recently discovered that isoprene, when it is altered by exposure to the sun, can also react with nitrogen oxides emitted from the burning of gasoline and from coal burning to produce particulate matter. Scientists discovered the link to plant-produced particulate matter in 2004, but the researchers involved in this study are responsible for making the link between the pollutant and anthropogenic nitrogen oxides. Particulate matter, when inhaled, can cause heart and lung problems, and can also affect air visibility and can make bodies of water more acidic when they are released into the air.

So, should we cut down all of our trees to solve our air pollution problems? The answer is no. The compounds produced by trees are reacting with human-produced compounds, which underscores the need for us to examine our own actions.

Photo courtesy of blmiers2 via Flickr.


It's better to BEE careful!

Bees and other pollinating insects are responsible for pollinating a whole range of agricultural crops, especially fruits and vegetables, many of which will fail in the absence adequate pollination. Consequently, the value of bees is much more than the honey they produce, and is monetarily estimated in many billions of euros in Europe alone, where one third of our foodcomes from plants pollinated by insects.

The declination of bee populations have been reported for some time now, attributed to many factors including mobile phone networks, parasites, diseases and now a group of agricultural chemicals called neonicotinoids. Neonicotinoid insecticides have been increasingly used in agriculture in the recent past. Neonicotinoids can be applied as seed coatings when crops are being sown, and the emerging seedling takes up the insecticide, and in many cases retain its properties right through its flowering period and until harvest. This kept pests at bay with minimum difficulty for farmers, but now it seems, with possible implications for pollinating insects.

Throughout the research and development stage, agricultural companies released data indicating that neonicotinoids were safe in relation to the bee population. However, it is now known that while the insecticide does not kill the bee, it does cause them to become disorientated and hence can’t find their way back to the hive. In addition, new data also shows that synergistic effects with a commonly used group of fungicides can render the neonicotinoids much more poisonous than originally thought.

But, there’s a snag in the line- the data is not conclusive and a ban to these chemicals will certainly cause difficulty for farmers- so what is to be done?

This is a perfect example of a time when it’s better to “play it safe”, and that’s what the European Commission is going to do. Despite fierce lobbying by the chemicals industry and opposition by countries including Britain, 15 of the 27 member states voted for a two-year restriction on neonicotinoid insecticides. This ban will allow time to determine whether bee populations will stabilise and recover- if this is the case, it would be a fairly conclusive indication as to whether neonicotinoids are at the root of the problem of honey bee decline and further action can be taken from there on out.

To follow the story as it develops, see here:

Image courtesy of K.L. Heong

Atmospheric carbon dioxide about to reach 400ppm

As a new round of climate talks gets underway in the German city of Bonn, the NOAA's Earth Systems Research Observatory, perched high on Hawaii's Mauna Loa volcano, expects the CO2 level to reach 400 parts per million in the next few days. This site, at 3800 metres above sea level, far from densely populated areas with high CO2 emissions, has been monitoring carbon dioxide for half a century, and is considered the global reference location for these measurements.

This greenhouse gas normally shows its annual peak in the rising saw-tooth pattern in mid may, with the net annual peak level rising steadily year on year. It peaks before spring growth in the northern hemisphere starts to absorb the gas, releasing it during the northern winter. On April 25th the level reached 399.72ppm, and hourly readings have topped 400ppm six times in the last week. Charles Keeling, whose curve describes the rise in CO2 over the last half century said that if the line isn't passed in this year's peak, then it certainly will be next year. With two weeks to go before the annual peak, it seems likely that it will. The consensus safe level of atmospheric CO2 in the climate change community is considered to be 350ppm in order to keep Earth from warming less than two degrees Celsius. It has been over two million years since levels were this high, and the Pliocene world was much warmer than ours.

Image credit: NOAA.

Goethe: Poet, polymath and mineralogist (1749-1832)

The poet of the German enlightenment is best known for works such as 'The sufferings of young Werner' and the quintessential mad scientist story 'Doctor Faustus' (in which the protagonist sells his soul to the devil for knowledge). In an age when anyone with a pretence to an education was polymathic, he was widely acknowledged as a leading intellectual, and had many other important accomplishments that are now overshadowed by his artistic fame.

Amongst other things he was a minister in the Duke of Weimar's privy council (the term originated to describe those intimate enough with the ruler to talk to him when on the privy), ran mines, acted as a political advisor and organised museums and collections. He was a reputed research scientist, famed for his 'study of colour', a meteorologist (he designed a barometer), botanist (author of the metamorphosis of plants), anatomist, geologist and mineralogist. He also dabbled in alchemy (closely related to mining in his day), as did most early 'scientists', including Newton.

His interest in rocks started in his early twenties, when he was made the Duke's mining supervisor, reopening the copper mine at Ilmenau in 1784 in order to increase state revenues. He studied silver ores and coal measures for his patron, and helped develop the mining industry in the state of Weimar (at this time Germany did not exist, its current territory was a patchwork of small feudal states). He maintained a wide circle of contacts throughout Europe and the New World, exchanging suites of rock samples and translating important scientific works between languages to further their dissemination. , He participated in the great development of international scientific exchange of the eighteenth century, when networks of interested amateurs evolved into professional scientists and laid the foundations for many modern disciplines. No 'scientist' in those days restricted themselves to a single study area or activity.

He travelled widely in connection with his various works, exploring geology and gathering rocks as he went. He was such an assiduous collector that he promised himself repeatedly before trips not to gather and lug any rocks, and broke it every time (something all geologists do, myself included). His field trips included the Hartz mountains, where he studied granite, and Italy, where he explored Vesuvius, guided by the British consul and first volcanologist Hamilton.

When he died, his mineral collection amounted to nearly 18000 items and was one of the largest private collections in Europe. They are still as he left them in his home in Weimar (the Geothehaus), stored in the same annex and cabinets he designed. He began gathering rocks in the 1770's and continued until his death, a span of over half a century. Remember that until the mid 19th century, 'minerals' included rocks and fossils, encompassing anything non archaeological that came out of the Earth. The separation of mineral studies into petrology, mineralogy and palaeontology was a nineteenth century affair, a development which he contributed to. This work was done in in Europe's great museums, which developed after the French revolution into the research institutions we know today. Goethe was one of those who shaped the vision of a museum as a store of samples for use in teaching and research. In 1804 he became the Weimar superintendent of museums, which he thought his most important administrative duty, shaping them into research institutions rather than aristocratic curiosity cabinets.

Geologically he was a student of Werner, the pillar of the Neptunist hypothesis (which was anti catastrophist and thought all rocks were precipitated from water) and pioneer of a standardised description protocol and terminology for rocks and minerals, based on German mining practise. Many words used in mining to this day are German in origin, since they were acknowledged the masters of geognosy (as mining and structural geology were then labelled). He published ' a short classification and description of the various rocks in 1786, and developed the systematic study of petrology, though his interpretations are now dated.

Goethe saw the purpose of his personal mineral collection as gathering representative suites of rocks from as many places as possible. By studying such suites, and comparing results with others worldwide, he hoped to create the preconditions for developing a theory of the Earth based on facts rather than supposition. He was the forerunner of the modern museum mineralogy department, and extended this philosophy to the state's museums when he administered them. He once said that rare or beautiful specimens were not the objective of his collection, but the most geologically informative

He recognised that a non speculative and empirical theory of the earth was beyond a single person, and needed a thorough description of global geology in standardised terminology. He therefore sought to establish a corresponding network worldwide in order to collate one based on shared mapping and rocks. The objective was to arrive at a standardised description and mapping of the world's rocks in order to theorise upon, putting the horse before the cart, unlike many speculators on his era. He wasn't the only one engaged in this project, but his fame and authority gave him access in corridors of power and allowed his contribution to be substantial.

In 1810 he published his Theory of colour, which he saw as his most important work. He viewed his science as a greater contribution than his art to civilisation, and in his published conversations with Johann Eckermann he is quoted as saying 'As to what I have done as a poet,… I take no pride in it… But that in my century I am the only person who knows the truth in the difficult science of colours – of that, I say, I am not a little proud, and here I have a consciousness of a superiority to many'. He belonged to the romantic movement, who tried to reconcile reason and passion, and integrated this approach into his scientific work.

Modern historians of science dismiss him as a dilettante, though he was a pioneer of a standardised mineralogy and petrology. They ignore the scientific context of the time, in which most people who studied science were 'amateurs', usually either wealthy or educated rural provincials trying not to die of boredom out in the sticks (iguanodon was discovered by a country doctor). The amateurs usually reported their findings and sent specimens to the budding professional scientists in museums. In the Earth sciences, he was not an amateur, being tied to the latest work in what was then the world centre of Geology: Germany.

They also make the mistake of judging his scientific works in the light of current knowledge, rather than in the context of what was then the known. Each scientific generation tends to disparage those before as ignorant, and earlier on the mythical climb 'up the ladder of knowledge and enlightenment out of the depths of superstition and ignorance'. His incorrect geological interpretations were orthodox in his day, and his contribution to the progress of geology as a discipline is undeniable. He strikes me more as a genius who made an impact in many areas.

Thanks to his fame as an author, and consequent access to wide (and high) social circles, he was able to introduce science as a fashion into the aristocracy. This brought financial patronage into the scientific world from sources that would otherwise not have been interested. He encouraged aristocrats who ruled their statelets to extend their curiosity cabinets into research and teaching collections, and helped develop the scientific education that made Germany a rich and powerful industrialised nation by the end of the century. The bait he used was geology, and its application in increasing mining revenue.

He is remembered in the mineral goethite, as well as the German governmental international cultural organisation: The Goethe Institut

Portrait of Goethe in the Roman Campagna, 1797, by Tischbein. Image credit: Martin Kraft/Stadel Museum, Frankfurt.