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Geography of data

March 18, 2011

OK. For someone like me this map is just ridiculously addictive. Produced by Revolver Maps, it shows the locations of everyone who’s visited the Muddle since March 5th (2011). If you click on the map it will take you to their page where you can find out more about the locations of all those dots.

The points on the map are a fascinating result of a combination of population distribution, language, technologic infrastructure (and wealth), and the miscellaneous topics on which I post.

Hits on the Muddle (blue circles) after two days, overlayed on a population density map of the U.S.. (Population density map from the USDA).

Overlaying at the location of hits after two days, on a population density map of the U.S. shows the obvious: the more people there are, the more likely it is that someone would stumble upon my blog. The eastern half of the U.S. with its higher populations are well represented, as is the west coast, while the hits in between come from the major population centers.

The pattern of hits from Australia shows very precisely that the major population centers are along the coast and not in the arid interior.

Map showing the hits on the Muddle (March 5-7) from Africa versus population density.

Africa, however, tells a much different story. The large population centers are along the equatorial belt of sub-Saharan Africa. But even now, there are very few if any hits from that region. I suspect that’s largely because of language and lack of access to the internet. The Muddle is not exactly the most popular on the internet, so it probably takes a lot of people on computers for a few to find their way to it. Contrast sub-Saharan Africa to South Africa, which is relatively wealthy, uses English as its lingua franca (working language), and has seen at least a few people hit the Muddle.

Members of the Commonwealth of Nations. Most of these countries were once part of the British Empire. (Image from Wikimedia Commons User:Applysense.)

Language also plays in big role in the pattern of hits from Europe and Asia. There are many English speakers in western Europe, a very high population density, and so a lot of hits, but the British Isles, as might be expected, are particularly well represented. Similarly in Asia, the members of the Commonwealth are show up disproportionately.

From the middle east, there have been a several hits from the wealthy small states like Bahrain and Qatar, but also a number from Egypt. The Egyptian interest in particular seems to stem from my posts on the recent revolution. No-one from that part of the world has commented on any of it so far, so I have no idea if they find the posts positive, negative, indifferent or whatever. I’d be curious to find out, since even negative feedback is important.

On the note of current events, my post on the plate tectonics of the earthquake in Japan has engendered quite a number of hits, and some positive feedback in the comments section and via email (one from a Japanese reader). In the week since the earthquake more than half the hits to the Muddle have been to that post, largely because it’s been popping up on the front page of the Google search for “plate tectonics earthquake Japan”.

Recent visitors to the Muddle on March 15th, 5:00 AM.

It has been fascinating seeing people from so many different countries hitting my blog. Since most don’t comment, or drop me a note, blogging often feels quite lonely, like I’m just talking to myself. Self-reflection was the original purpose for this blog, and I find that combining writing and graphics really works for me as a way of expressing myself.

Yet, this blog would not be public if I did not have an insatiable urge to share. So thanks for reading, and don’t be afraid to comment. I am a Montessori middle school teacher after all, so I tend not to bite. Although, if you do try to post a comment and it doesn’t show up it may be because it got caught in my spam filter; there is a 1000:1 ratio of spam to legitimate comments so it’s hard for me to catch any mistakes. Sending me an email should fix that though.

Citing this post: Urbano, L., 2011. Geography of data, Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Seismic vibrations of the heart

February 19, 2011

You should be able to see three heartbeats on the bottom line (labled Z), though the Z obscures part of one of the waves.

We were working on plate tectonics last week, and the conversation went from earthquakes to heartbeats.

I think it started with the question of, “How do we know what the inside of the Earth is like if no one’s been down to see it?”

I agreed that we’ve not even been down to the bottom of the crust because the heat and pressure would collapse any hole we tried to drill. I did not mention that terrible movie, “The Core”, because beyond maybe the first ten minutes where there is some actual speculative science fiction, it’s really not worth seeing.

But beneath the crust, how do we know how thick the mantle is? How do we know that the inner core is solid metal (mostly iron) while the outer core is liquid metal?

Not wanting to go into too much detail I tried to explain about seismic waves. Different types can go through different materials and if you monitor their reflections off different parts of the Earth’s interior you can puzzle out the layering and composition. I just gave the simplest demonstration: if you tap a piece of wood with you knuckle, could you tell that it was wood and not metal? What if you tapped a bucket, could you tell if it was full of water or not? Well seismic tomography work in much the same way, except that you’re usually picking up the reverberations from the earthquake rather than making it yourself by hitting the bucket. There’s also a bit more math involved.

But tapping the bucket gives a quick easy feel (pun intended) for the process. My students at least seemed satisfied.

So then I pointed out that you could use an app called iSeismo, to detect seismic waves. Both the iPhone (and its variants) and the iPad have accelerometers that can be used to pick up motion in all three dimensions. My students from last year remembered it, and at least one already had it loaded on his phone.

A quick test showed that the phone’s pretty sensitive. You can pick up two people jumping together all the way across the room. This part of the demo is nice because it helps prove that seismic waves from earthquakes can go very far. You can also see the little squiggles as the waves are picked up.

I did not try it this time, and I’ll need to confirm if it will work, but since the time on the phones should be well synchronized over the network, and iSeismo can output the actual data, we should be able to use three iPhones to triangulate the location of the jumpers. This might work in nicely with geometry now that I think about it.

Checking for a heartbeat using iSeismo.

Anyway, finally, a student asked if the phone might be able to pick up his heartbeat if he lay on his back.

We tried it. Lying on his back on the floor while holding his breath, we could see his heartbeat quite clearly.

Citing this post: Urbano, L., 2011. Seismic vibrations of the heart, Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Oil does not come from dinosaurs.

August 3, 2010

Phytoplankton (image from NASA).

There’s a nice article in the New York Times on the fact that oil, petroleum, did not come form dead dinosaurs, but rather from the microscopic plankton that died and fell to the ocean floor.

The idea that oil came from the terrible lizards that children love to learn about endured for many decades. The Sinclair Oil Company featured a dinosaur in its logo and in its advertisements, and outfitted its gas stations with giant replicas that bore long necks and tails. The publicity gave the term “fossil fuels” new resonance. – Broad, 2010

It’s easy to forget how pervasive is the idea that oil comes from dinosaurs. Broad’s article is a nice reminder that:

Today, a principal tenet of geology is that a vast majority of the world’s oil arose not from lumbering beasts on land but tiny organisms at sea. It holds that blizzards of microscopic life fell into the sunless depths over the ages, producing thick sediments that the planet’s inner heat eventually cooked into oil. It is estimated that 95 percent or more of global oil traces its genesis to the sea. – Broad, 2010

How do we know?

[I]n the 1930s. Alfred E. Treibs, a German chemist, discovered that oil harbored the fossil remains of chlorophyll, the compound in plants that helps convert sunlight into chemical energy. The source appeared to be the tiny plants of ancient seas. – Broad, 2010

Phytoplankton bloom off the Carolina coast. (Image from NASA).

We tend to find a lot of oil in the deltas of the great rivers because the rivers provide nutrients for the microorganisms to survive and layers of sand and clay sediments that trap the oil and natural when they’re produced.

The article also ties the location of oil production to the geography of plate tectonics.

[W]hen Africa and South America slowly pulled apart in the Cretaceous period, forming the narrow beginnings of the South Atlantic. Big rivers poured in nutrients. A biological frenzy on the western shores of the narrow ocean ended up forming the vast oil fields now being discovered and developed off Brazil in deep water. – Broad, 2010

Citing this post: Urbano, L., 2010. Oil does not come from dinosaurs., Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Integrating Eyjafjallajökull

April 29, 2010

Second fissure, viewed from the north, on 2 April 2010 (from Wikipedia)

Current events often generate the teachable moments we’re always seeking in order to strike students’ imagination. The eruption of Eyjafjallajökull is a prime example. I’ve already used it to point out the intersection of geothermal energy and plate tectonics, but there is so much more.

The second eruption in Eyjafjallajökull. Seen from Fljótshlíð on 20 April 2010 (from Wikipedia).

Eyjafjallajökull has been a wonderful subject for the art of photography. The image above is a great example but the time-lapse photos have been excellent. The photo to the right captures not just the stars streaking across the sky with a three minute exposure but the fiery red arcs of the volcanic ejecta.

The MODIS instrument on NASA's Aqua satellite captured an ash plume from Eyjafjallajökull Volcano over the North Atlantic at 13:20 UTC on 17 April 2010 (from NASA via Wikipedia).

One of the major benefits of the space program so far has been its Earth observing satellites. There is so much going on in the image to the left that it’s hard to know where to start. Why are there all those clouds over Iceland? (warmer land mass creates convection); what’s with the two plumes from the volcano, one concentrated high level and one disperse low level plume; fjords on the upwind side of the island and the straightened coastline on the lee; greenish plumes of glacier-ground, rock flour discharging into the ocean.

Dust particles suspended in the atmosphere scatter light from the setting sun, generating 'volcanic lavenders' like this one over the flight path of Leeds-Bradford Airport in England during the aviation shutdown. (from Wikipedia).

The dinosaurs were done in either by an asteroid impact in the Yucatan or the eruption of the massive flood volcanoes in Deccan, India, or quite probably both. Both of these events launched an enormous amount of ash, gas and fine particles into the upper atmosphere, blocking sunlight, causing global cooling. Well the ash from Eyjafjallajökull and the sulfur dioxide gas may be having a similar effect on Europe, and if there’s enough of it, on the world. The 1992 eruption of Mt. Pinatubo cooled the globe by about half a degree Celsius.

Citing this post: Urbano, L., 2010. Integrating Eyjafjallajökull, Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Waves and earthquakes

February 9, 2010

There are a lot of Earth Science applications that deal with waves. Seismic waves from earthquakes are a major one that is particularly pertinent after the recent Haitian earthquake. There are quite a number of lesson plans dealing with seismic waves at Larry Braile’s website. Most of the lessons are as practical demonstrations pdf’s and some use downloadable software (Windows only unfortunately), but there are some online applications as well.

In terms of online resources, the IRIS network, produces nice maps of recent earthquake locations. It also has a good page with “Teachable Moments” regarding recent earthquakes. These include the above video of why the Haitian earthquake did not produce a tsunami.

Although it’s not directly related to waves, I particularly like the thermal convection experiment on Braile’s website. It provides, with a baking dish, a sterno can, some water and some thyme, a great example of the convection in the Earth’s mantle that drive plate tectonics.

Citing this post: Urbano, L., 2010. Waves and earthquakes, Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Cave Formation in the Ozarks

October 8, 2012

Ceiling of Twin Cave.

Rain falls.
Some runs off,
Some seeps into the ground.

Water drips from the tips of limestone straws on the roof of Twins Cave.

It trickles through soil.
Leaching acids, organic,
Out of the leaf litter,

But even without these,
It’s already, every so slightly, corrosive,
From just the carbon dioxide in the air.

Gravity driven,
The seeping water seeks the bedrock,
Where it might find,
In the Ozark Mountains,

Planktonic shell (from Coon Creek which is 30 million years old, compared to the limestone rocks in the Ozarks which are 300 million years old.)

Microscopic shells, of plankton,
Raining down, over millenia,
Compacting into rocks,
In a closing ocean,
As North America and Africa collide,
From the Devonian to the Carboniferous.

Orogenic uplift,
Ocean-floor rocks,
Become mountains,

Appalachians, Ouachitas,
The Ozark Plateau.

The collision of North America and Africa uplifted the limestone rocks from the closing ocean (the Rheic Ocean) to create the Ouachita Mountains and Ozark Plateau. (Figure adapted from iimage by Dr. Ron Blakey -

Limestone dissolves,
In acid water.
Shaping holes; caves in bedrock,
Where we go,

Crawling through the "Brith Canal".

Citing this post: Urbano, L., 2012. Cave Formation in the Ozarks, Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Character Amid the Ruins

March 21, 2011

People are made of flesh and blood and a miracle fibre called courage.

— Mignon McLaughlin, The Neurotic’s Notebook, 1960 (quote via The Quote Garden.)

The character of an individual, and even of a people, is best identified in periods of adversity. That was one of the things that came up when my students discussed ethics, morality and poverty. With all the talk of how the Japanese people are reacting to last week’s earthquake, with a relative lack of looting and criminality, it is worth visiting Jesse Walker’s article in Reason last year that really looked at how people really respond to disasters. It turns out, that from Haiti to New Orleans to San Fransisco in 1906, people are much more restrained and disciplined than we’re lead to imagine.

Walker reviews Rebecca Solnit’s book “A Paradise Built in Hell: The Extraordinary Communities That Arise in Disaster” which points out the “little utopias” that arise in disaster hit communities.

Walker also points out the incongruity between our expectations and actual observations:

It isn’t unusual for a TV reporter to get his facts wrong. It’s rarer for the images that accompany his dispatch to flagrantly contradict what he says. But on January 21, broadcasting in the aftermath of the earthquake that devastated Haiti, CNN correspondent Ivan Watson fretted about “chaotic crowds” as the camera showed people who were calm and patient. When Watson announced that we were watching a “chaotic scramble” onto a rescue ship, this was illustrated by a group of refugees carefully, methodically passing a baby onto the boat.

–Walker (2010): Disaster Utopianism on

Citing this post: Urbano, L., 2011. Character Amid the Ruins, Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

Volcanic eruption in Japan: Shinmodake

March 15, 2011

Shinmodake Volcano in southern Japan (center). This picture predates the big earthquake. Image from NASA Earth Observatory: Shinmoe-dake Volcano Erupts on Kyushu..

The Shinmoedake Volcano erupted on January 19th after being dormant for two years, however, two days after the big Japanese earthquake, it began spewing ash once again. The two are not necessarily connected.

Volcanos and convergent margins go together. Typically, the plate being subducted melts as it is pushed deeper into the Earth and temperatures rise. It also helps that the water in the crust and sediment of the subducting plate makes it easier to melt, and makes the resulting magma much more volatile and explosive.

The subducting plate melts producing volatile magma.

But although Shinmoedake is in Japan, it is not on the same tectonic boundary as the earthquake. The northern parts of Japan are where the Pacific Plate is being subducted beneath the Okhotsk Plate. This volcano is connected to the subduction of the Philippine Plate to the south.

The large earthquake's epicenter and the Shinmoedake volcano are on different plate margins. Image adapted from Wikimedia Commons user Sting.

This does not necessarily mean that the two occurrences are totally unrelated. Seismic waves from the big earthquake could have been enough to incite magma chambers that were just about ready to blow anyway.

The map below is centered on the series of craters in the region of the erupting volcano.

View Larger Map

Citing this post: Urbano, L., 2011. Volcanic eruption in Japan: Shinmodake, Retrieved February 23rd, 2018, from Montessori Muddle: .
Attribution (Curator's Code ): Via: Montessori Muddle; Hat tip: Montessori Muddle.

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