Scientists Unravel One Of The Keys To Life On Earth — And It's Right Beneath Your Feet

blue globe.gif

David Bercovici

An idealized version of the earliest plate tectonics. The blue areas are the rigid plates. The red, yellow, and green areas are the boundaries.

Scientists are constantly on a mission to untangle how Earth alone among the planets was able to evolve complex life.

Scientists know that Earth's past internal movements of the tectonic plates under our feet make our planet one-of-a-kind — they trapped carbon dioxide which helped make our planet habitable.

A new study, published in the April 6 issue of the journal Nature, may have figured out the mystery of how these plates formed — and why only Earth has them.

Why plate tectonics is important

USGS

These are the Earth's major tectonic plates. The arrows show which way the boundaries are moving.

Plates cover the entire Earth, and their boundaries play an important role in geologic happenings. The movement of these plates atop a thick, fluid "mantle" is known as plate tectonics and is the source of earthquakes and volcanoes. Plates crash together to make mountains, such as the Himalayas. They leave trenches where one slips beneath the other. They make giant rift valleys and ridges when going their separate ways.

The process is actually very important to life on Earth. Several billion years ago, the surface of our Earth began forming into puzzle pieces called plates. This process trapped our atmospheric carbon dioxide into rocks and stabilized our climate, making Earth habitable.

A Mylonite mystery

How this developed has been a mystery for centuries. But one feature present at all plate boundaries could be the clue needed to crack the mystery: a rock called mylonite.

Mylonite rocks show up at every plate boundary and have puzzled scientists since at least the late 1800s.

"Their presence is a bit of a mystery," study researcher David Bercovici, of Yale University, told Business Insider. "There are well-known observations of mylonite at all different kinds of plate boundaries and there's been a long debate about what causes them."

Wikimedia Commons/ Woudloper

Mylonite from the Southern Alps

Mylonite is a highly deformed rock, which makes it the size of a small piece of grain. Small grain-size equals a weaker rock. Since these rocks occur around all plate boundaries, their deformation and subsequent weakness piqued Bercovici's interest.

"It was a big motivation for developing this theory in the first place," said Bercovici who worked with Yankick Ricard of the Université de Lyon on the study.

How rocks define Earth's plates

David Bercovici

Using a set of laws to describe how grains evolve and "many many pages of physics," Bercovici and Ricard were able to calculate how the birth of plate tectonics may have come about. Bercovici began with the idea that, back when Earth was just a ball of hot goo, certain parts of the surface would become cooler than others and sink. These areas were called downwellings. "You can see this happen in a cup of coffee or soup," he said.

Downwellings cause deformation of the sinking material as it bends downward. In the globe to the right, the blue is a sinking area on the Earth's surface, the beginnings of a plate boundary.

"The idea of our model is that if I deform a rock, I'll actually make the grains smaller." Smaller grains equal weaker rock and a weaker rock means it will more easily succumb to future deformations.

David Bercovici

This creates a feedback loop where Earth's slowly cooling crust accumulates weak zones. "And you accumulate enough of these weak zones and you'll eventually get plate boundaries," he said.

In the globe to the right, the sinking from the red globe above has created a convergent boundary — in blue — where plates move together. This pulls on the rest of the Earth's surface, eventually forming a divergent boundary — in red — where plates move away from each other. Once a piece of Earth's surface is enclosed by boundaries, it becomes a moving plate.

On Venus, damaged areas of the crust were never able accumulate into boundaries because it was too hot. The weak zones healed relatively quickly and the planet was never able to develop plate tectonics.

Venus' plates never trapped CO2, never cooled, and the impact on the planet's atmosphere makes it uninhabitable.

Solar Eclipse: May 20, 2012

Click on image to enlarge

Reflection on My Reflection

While working with the software for the digital reflection, I began to really appreciate the ease at which "live" lessons could be recorded by teachers to enhance student understandings. Although I haven't done it yet, I plan to record future graphic presentations (fancy term for PowerPoint), and have them available for my students who might miss the actual presentation because of illness or other legitimate reason for an absence. I also have to thank Jeff for explaining how easy it is to resize embedded information in our blogs on that first day of class, because I had to recall that information to neatly fit my digital presentation in the space available. Thanks again to all who helped me increase my techknowledge (pun intended) throughout the semester.  -Carl

Digital Reflection

Student Seating and Classroom Management

Another seemingly obvious epiphany that I had recently is how important something as simple as how the seating in a room can affect student participation and lesson comprehension. Most science classrooms are designed around desks, and they invariably force students to sit at odd angles in relation to where most of the instruction takes place. I understand the need to have student-centered learning, however, having students facing away from the focus of instruction does very little for a 14 year-old’s comprehension. The standard single seats from the 70’s and 80’s seem to be traded out at an increasing rate for more social desk groupings. This is even taking place in non-science classrooms. I have recently discussed this issue with one of my cooperating teachers, and he stated that he can understand my point of view, especially considering the few number of labs we do that require desk usage. With the fundamental purpose of teaching being the transfer of understandings to our students, I feel that anything that promotes this idea should be embraced. The classes I am teaching this semester are all taking place in portable rooms that have no distinct designation between Social Science, English, or Earth Science. However, the classrooms where science isn’t being taught all have conventional single seating, and those teaching science all have table group seating.

            I see the benefit of having tables available for students while conducting lab work, but during the other 80% of their time in the classroom, the table group seating works against their ability to remain focused. Having experimented with multiple table arrangements over the past school year, I have seen how quickly students drift away from the central focus of the lesson when they are staring directly at another student. Some of my best students have been distracted by students around them when seating assignments and arrangements change. Unfortunately, I don’t see any one correct answer to this problem. Limited space and larger numbers of students in every class will likely just exacerbate the problem. Facing a student in any direction away from the focus of learning is simply telling them that what is going on isn’t really important. Students know that the direction they are facing is where the information is, whether that information is content or socially based.

The Bottom Line

Over the past six months of teaching I have frequently reminded my students and occasionally myself what the reason is for them being in my class. It isn’t to get good grades, nor is it to please their parents. The reason that seems to get muddled by all of its byproducts is the attainment of knowledge and understanding. I know this sounds obvious and simple, but it is amazing how often we lose sight of this while interacting with students. I completely understand that students want to get good grades. I strive for this as well in any class I am enrolled in. But when I remind students that learning is the true reason why they are in the seats, they look at me like I am inconveniencing them with some silly fact.

            The reason I need to occasionally remind myself about this, is that sometimes a student might ask me a question that isn’t directly connected to the lesson being taught, but is nonetheless a valid inquiry based on a real desire to know more about a particular subject. With time always being a commodity I am short of, I will try to give a brief answer that I think satisfies the student’s question and quickly move back to the subject at hand. This particular scenario came up just the other day when I was discussing the distances between stars and the speed of light. I had a student ask me about my feelings on UFOs and whether I thought we might ever visit other solar systems. I answered the question which was asked, but looking back, I feel I may have missed a tremendous opportunity to provide additional information, not just to this student, but to the entire class. My simple answer of the distances being so vast could have been better executed if I were to go through the math of question. I could have had the class, as a group provide the information about how far light travels in a single year (approximately 5.9 trillion miles), and let them decide whether they felt we would ever make such a journey. Instead, I was focused on cramming the last few hours of review in prior to their CST exams and potentially lost a teaching/learning moment that might have lasted them the rest of their lives.

CST Prep

With the science CST sections coming up in about a week, we are currently looking at different ways to solidify the students’ understandings of the information covered over this school year. Although I believe that there is a definite need for some sort of standardized way of evaluating the effectiveness of teaching, I am not sure this is the best method. Whenever told about an upcoming state mandated test, it seems that the first question asked by the students is whether it will count toward their grades. Each teacher understands what the students are really asking, “Do I really have to try on this test?”  This is a dilemma that is faced every year as teachers try to impart upon their students the importance of a test that has no immediate affect on their lives. To try and get students to “do their best” without a reward for doing well, or a negative impact for doing poorly is simply not effective.

      In an effort to help students demonstrate their abilities and reinforce content understandings attained throughout the year, we are looking to have an extra credit review session. This will benefit both the students and the school, as they should be better prepared for the CSTs and allow them to gain extra credit to positively affect their own grades. Even with such an incentive, many students still will not take part in the session.  That being said, I am looking for additional ways to better solidify understandings late in the school year. I want to reinforce key concepts not just for the sake of higher achievement on the CSTs, but for the true reason for their learning, to help them commit key concepts to their long-term memory. I predict that I will be wrestling with this dilemma each year around this time throughout my future teaching career.

EDCHAT POST #2

Natural Born Teachers

One of the more interesting comments/topics presented during this week’s edchat was the question of whether the participants felt that there was such a thing as “a natural born teacher”. My opinion on this is that teachers need to be leaders, and yes some people possess that special “something” that helps them succeed in leading others, but these are few and far between. The better, more complete answer might be that although we may have the basic foundation for becoming a strong leader or teacher, it is much more dependent upon being taught how to lead, and given strong examples to emulate.

The big difference between leaders and teachers is that to be a teacher you must be a leader and have the ability to convey valuable information to audiences quickly and effectively. Knowing what information is critical to a class’ learning and being able to present that information in a digestible fashion can prove to be the greatest hurdle prospective and seasoned teachers face. I myself do not pretend to have all of the answers, I only know what I have observed in others, and feedback provided to me from those who have critiqued my own teaching methods.

      I believe that a skill such as teaching, like any other skill can atrophy over time and needs attention to remain at a constant level of effectiveness. This is where a PLC or PLN can come into play. Through collaboration and communication with others in the profession, teachers can be constantly exploring new ways of presenting information to their students. Just as the information we teach gradually changes, so should our pedagogical style. Teaching is a never ending evolution and refinement of leadership and communication skills. I personally hope to be a better teacher on my last day of teaching than I was the day before. 

What guides my decisions as a teacher.

Whenever I come across a dilemma that requires me to evaluate how different choices will affect my students, I try my best to think about how that decision would affect my daughter if made by one of her teachers. Although she is a few years older now than when this photo was taken, I still see her this way and probably always will. I want the best for my daughter, and I am sure that the parents of my students feel the same about their children. I don't want a teacher to make my daughter's life easy. I want them to challenge her, while still respecting her and helping her. Teachers and parents have two very similar tasks in this respect. They both are trying to prepare kids for their futures away from the direct support of their families. They are also trying to make them the best adults they can be. The other day I had a student who was failing my class approach me about advancing him some extra credit that he would be completing in the future, so he could remain active on one of the school's sports teams. As much as I would like to have given in and let him off the hook, I knew that I wouldn't be truly helping him understand that actions have consequences (not in the California Content Standards). At that moment, I thought about what his parents would have wanted me to do, and I thought about how I would feel if he were my son. In the end I told him that I will work with him to make up any deficits in his grades by allowing him to turn in missed assignments, but that I would not advance him the upcoming extra credit. Although it is not our job to be our students' parents/families, I do feel that we must take every opportunity to provide guidance not only on content, but also on life and growing up. 

Embracing Our Inner Nerd!

 Each time I am introduced to a new class, I try to think of something interesting to say that might inspire them, and have them looking forward to being in my class. I have developed a relatively generic speech that explains what I expect of my students, and the general policies of the classroom. However, I have recently decided to modify my introductions to include something that I hope becomes even more important during the course of instruction. I now ask them to embrace their inner nerd. I tell them that it’s alright to actually think some of this is cool.  I go on to explain that I try my hardest to present material that at least I find interesting and cool. I try to explain to them that they shouldn’t feel bad for quietly thinking or saying to themselves, “That’s cool”. I then go on to explain that applause will not be required, unless of course they are truly moved to provide it.

           

The other point that I try to accentuate is that it is completely OK to come up with a wrong answer when I ask for input. I usually try to relieve any fear of looking foolish in front of their peers by assuring them that after the next three years, they may never see another student in that particular class again. Although I am going for a laugh at this point, I do assure them that high school does not predict the rest of their lives, and that they should have nothing to fear while in my class. 

What Learning Looks Like (underwater)

Just another shot of my daughter expanding her horizons. 

* All Clownfish are "Nemo" to a 5 y/o.

EDCHAT POST #1

Trying to follow edchat is one of the more difficult tasks a new teacher can undertake. However, with so many different conversations and posts occurring simultaneously, I found myself homing in on one post in particular. The post read “School's function is 2create workers 2 fuel our economy, we need 2 change school, because the workers we need have changed as well.”

My initial reaction to this statement is that it seems to be logical, but then it started to sound a little Orwellian to me. Looking at schools as a factory to produce workers is a little narrow in its scope. Sure, we do try and produce individuals that are capable of being productive workers, and contributors to our society, but schools need to strive for so much more. Trade schools are designed to provide the skills a student would need to be successful in a particular occupation. Public schools are tasked with molding students into productive, knowledgeable citizens. Yes, we are creating workers, but we are also creating leaders, artists, writers, inventors, explorers, parents, politicians and everything else that we need as a society to prosper. In short, we are assisting families in turning their children into quality adults.

The final goal of all of these efforts should be to create an independent member of our community, while looking out for the interests of those who can’t fend for themselves. I understand that this is an ideal, and that human nature is a powerful force that cannot always be controlled or focused into a beneficial direction. The adage “You can lead a horse to water, but you can’t make him drink” is all too prevalent in our education system. However, that shouldn’t preclude us from working toward an ideal, no matter how lofty it may seem.

Day 1 of CP2 "Sink or Swim"

As with everyone else in the cohort, today was my first day full time at my school. Over the past few weeks, on top of everything else, I have been busy preparing lessons for my classes.  These lessons are designed to be taught beginning the first week after everyone returns from spring break. For this week, I assumed that I would only teach a couple of classes beginning on Thursday. Over the weekend I polished up my lesson design, and was fairly confident when I presented it to my CT this morning. When I gave my CT my plan for a computer based lesson, he took a quick look at it, and said that it looked great. Then he surprised me with something I should have seen coming, and am embarrassed to say that I did not. He asked me if I wanted to teach one of today’s classes. This was the first we had spoken of anything prior to my taking the class on Thursday. Before I could think about it, I instinctively said “Sure!”. Of course it was at that very second that I realized that I had been so consumed with preparing for later in the week and beyond, that I hadn’t even looked at today’s lesson. He politely offered to allow me to retract my impulsive agreement, but then again I heard myself say “No, I’m good to go!”.

I took copious notes while observing him during the prior class, and felt somewhat confident that I could carry this off without too much embarrassment or having someone contact the university to immediately kick me out of the credentialing program. As the bell rang, and it became my turn to take over the class, my CT quietly whispered that the principal will be dropping by, so “Don’t be nervous”. New class…check, first lesson…check, principal watching…check. I had visions of the George Clooney film “The Perfect Storm” running through my head. Well, after I settled in and began the  lesson, I was extremely grateful that my CT and my knee-jerk response had gotten me in front of the class as soon as possible. The students were amazing, and the experience allowed me to become their new teacher, and not just that guy who helps out occasionally. All in all, a good day. 

Oceanside High School/El Camino High School visits:

Having never been to Oceanside High School prior to our visit, I was amazed at how the campus resembled a small community college.  It was incredibly modern looking and seemed well designed. The science building was amazing all by itself.

1. How was technology integrated into the curriculum? Do you feel that it promoted student learning?

            The technology was primarily in the form of iPads that the students used at their desks to carry out the day’s instruction. The students immediately came into the classroom and began working “warm-up” questions that the teacher had prepared. The primary use of the technology was for assessment. Students would complete assignments and formal assessments on their iPads, and the teachers could receive immediate feedback on their understandings. This can really help during the formative portions of a lesson or unit. Although the fullest potential for the technology’s use isn’t realized through its incorporation only in assessments, this is a start to a much more student centered, and personalized form of instruction. The amount of feedback a teacher can receive through the use of these tablets, is far greater than any teacher can obtain through verbal communication alone.

2. Is there anything you saw that makes this classroom/school unique?

            The use of the technology isn’t what made the classes unique for me. It was the familiarity and comfort with which the students used the technology that I have not seen previously. They seemed as at ease with the iPads as they would be using pencil/paper for note taking, and completing assignments.

            In contrast, I have observed at several schools that don’t allow students to use any electronic devices. This extends to the computers that might be already present in the classrooms. Their concern is that the students will spend too much time on frivolous activities and not on their schoolwork.  This was shown to not be the case in the classrooms we visited at Oceanside High School. The students were productive and used the iPads appropriately.

3. What did you learn and how does it relate to the class questions?

            I found it interesting that the teachers were committed to ensuring that eventually each student could be issued an iPad, or similar device, to carry with them throughout the day, and take home for homework/additional support. I am having difficulty in understanding why this is so critical to the students’ learning, if they in fact have home computers and are able to access all applications and information from their homes.  My personal belief is that it would be much more effective if they had access to the tablets at school, and utilized their own computers at home.

            If a student is issued a tablet and therefore responsible for its condition, I can only see that a great many students will be responsible for reimbursing the school at the end of the year for damage incurred throughout the year. This can have the effect of not being equitable for all students considering the wide differentiation family financial situations. Where the replacement of a broken iPad for one family might be a non-issue, for another, it may very well be a financial impossibility. Having seen the condition of many students’ smart-phones over the past semester, I am certain that a fair amount of students will be buying the school new iPads if they are permitted to carry them to and from school. In speaking with my current Cooperating Teachers, I have been told that there really isn’t a tech gap among their students’ families. They all have internet access and capable computers at home.  In one of my classes, my CT has supplied web-books for use by each student while physically in the classroom. This has eliminated the need for booking computer lab time, and allowed students to accomplish most of their work digitally.

Autotune Science Mash-Up

What learning looks like on a rainy Saturday at CSUSM!

Learning an important lesson about inertia!

What learning SHOULDN'T look like!

What learning looks like!

This is the work they are doing in my daughter's kindergarten class!

Fantastic Social Justice Lesson

One the greatest impacts to me from my PLN occurred today. I was quickly breezing through some of the class tweets, and I noticed Mallory’s reference to “What does learning look like” and a photo link. Prior to reading her post and subsequently educating myself on the issue, I was somewhat ignorant to the atrocities being committed by Joseph Kony in Uganda. Like everyone who sees the video, I was appalled at the level of degradation we as humans are capable of. Then I recalled some of my students during CP1 asking why we would ever get involved in another country’s affairs. Why we would ever risk American lives in a foreign land? As this was asked during an Earth/Space Science class, I could not spend too much time on the subject. However, thinking back upon the question, I see a tremendous opportunity for a Social Science or English class to investigate where students stand on international policy and social justice. If facilitated well, this could be a significant and everlasting lesson for the students. They can understand the complexities of foreign policy and the decisions that affect all of our lives.

Having been on the business end of our foreign policy, I can understand how my students would feel about the costs in lives when we send troops abroad. The interesting part of the question is what is the point of commitment. When do we decide to become involved as a nation and intervene. I believe few students in our classes, would ever deny that something must be done to counter these crimes against humanity. The question for the students is how we get involved, and what if we are not wanted by the ruling party. These are the kinds of discussions that make me envy my Social Science brothers and sisters.