By George Hademenos, Physics Teacher - Richardson High School
As I alluded to in the President’s Column, my summer was filled with exceptional professional development (PD) opportunities that I would like to inform STAT members about and encourage participation in subsequent offerings. The first PD opportunity involves a week I spent at the School of Rock (SOR) aboard the JOIDES Resolution (JR) – an exploration vessel dedicated to drilling and collecting core samples below the ocean floor – which was docked in Cape Town, South Africa. This sounds wonderful but I am not a geology teacher. Why should I be interested?
The SOR is not exclusive to those who only teach geology or Earth and Space Science. It is open to all science teachers looking for instructional ideas to integrate geology into their science curriculum. In fact, the 2016 SOR class of 16 participants was as diverse as any one class could ever be. It consisted of both novice and veteran, formal and informal educators from the United States, Europe and Africa; science teachers and technology teachers; teachers who teach elementary and secondary students, college students, and the general public, coming from California, Florida, Tennessee, New Jersey, Texas, Illinois, North Carolina, Maryland, and Ohio, as well as France, Italy and South Africa. The “principal” of the School of Rock was Sharon Cooper with the International Ocean Discovery Program (IODP) and staffed with two outstanding faculty members: Dr. Larry Krissek from Ohio State University and Dr. Sandy Turner from University of California at Riverside. The SOR was in session for 9 days with each day’s activities described in a blog contributed by selected participants and summarized below.
Day 1 (05/29/2016): Are we there yet?
For many, the ride to school is a 5-minute car ride or perhaps 30 minutes in a school bus. The ride to this school was more involved. The JR was docked in Cape Town, South Africa. The trip involved 21 hours of flight time with an eight-hour layover sandwiched in between. Upon arrival at Cape Town International Airport and a bus ride to the port where the JR was docked, we signed in with security dockside and came aboard to find our room assignments, get pictures taken for our ship ID’s, eat lunch and unpack.
The first day concluded with an introduction to coring and an activity that represents the challenges confronted by JR to obtain core sampling of the ocean floor. A challenge of ocean coring is guiding a drilling process through rage depth of 3,800 meters of ocean and into the floor without visibly observing the process. One activity that embodied the challenges in ocean drilling involved a straw and multilayered cake. Who knew that geology could be so informative…and tasty too?
Day 2 (05/30/2016): Ocean sediment cores are an open book
During an expedition, the JR collects core samples 9.5 meters at a time using a 10-meter steel core barrel. Once it is brought onboard, the core sample is measured and marked in sections of 1.5 meters which are then used for various analyses by geophysical scientists. The scientists are challenged to compare and contrast the features of cores extracted from different drilling sites.
Color was likely an obvious difference you noted. Is there a relationship between color and the composition of the core? Scientists investigate this question using smear slides and a petrographic microscope. A small amount of core sediment is analyzed for the presence of biogenic material. Cores lighter in color (white, off-white, light beige or greenish yellow) likely have a biogenic origin. If over 50% of the sample is composed of biological remnants, then the core is an ooze; the presence of diatoms is a key indicator that the ooze is siliceous while coccoliths and forams (short for foraminiferans) are indicative of calcareous ooze. Darker cores (perhaps greenish gray or reddish brown) will likely have considerably less biogenic material.
In addition to core color, other characteristics such as geographic location and ocean depth can also reveal information regarding core composition. Terrigenous sediment (terrestrial in origin with relatively less biogenic material) is found relatively near the coasts. So how did that sediment get there? Erosion by water (rivers, streams, runoff, glaciers) deposits relatively large amounts of sediment on continental shelves and slopes. Eolian or wind erosion can carry small particles further distances from coastlines.
Calcereous ooze is typical of sediment in offshore, yet shallow (<4000 meters) water. And being in offshore sediment in both high latitudes and near the equator, we would say siliceous ooze has a bimodal distribution. But what about the sediments in the deepest waters? Terrigenous material is unlikely considering the far distances from the coast, and organisms in the oozes would not be viable in sediment under more than 4000 meters of water. That leaves the fine clay particles and pieces of iron oxide that result in the red clay in cores drilled in the deepest parts of the ocean.
Day 3 (05/31/2016): Field Trip
Today was an exciting day for the SOR participants because it involved the two words that every student (in this case, teacher) lives for during a school year: FIELD TRIP. Yes, we were stepping out of the classroom and into the field for a day of hiking and exploring the geology of Cape Town. Our planned itinerary for the day included several hikes, arranged and narrated by two local geology experts: Professors John Compton and John Rogers. We were very fortunate to benefit from the extensive knowledge and wisdom of two individuals in their chosen profession. They provided us with a lecture combined with an extensive hands-on field experience which made for the most ideal learning opportunity for SOR teachers – many of whom had never had formal training or coursework in geology. Knowledge aside, Professors Compton and Rogers were personable, approachable, very eager to respond to questions, and at times, downright funny.
HIKE 1: Three Anchor Bay to Sea Point Contact
During this stop, we ventured onto a beach site where we noted general displays of quartz, siltstone and granite. Of course, the shores of a beach are strewn with unique sea shells of all types, shapes and sizes, but the most fascinating observation (especially to the biology teachers) was the enormous-sized kelp that was stretched out along the shore.
As we continued on this hike, we ended at Sea Point Contact - the point where Charles Darwin ended his journey on Voyage of the Beagle in 1836. Most people, particularly scientists, correlate Darwin with biology, but many do not know that Darwin had a passion for geology and was actively investigating rocks and noting his observations.
HIKE 2: Signal Hill and Tafelberg Road
The second hike of the day was atop of Signal Hill where we were able to see a view of the harbor, Cape Town, the newly built soccer stadium for the 2010 World Cup of Soccer, and the surrounding mountains.
One site in particular that captured my interest was Robben Island which was also visible from our vantage point. This was where Nelson Mandela was imprisoned for many years for political crimes against apartheid. As we were listening to Professors Rogers and Compton speak about the geology of the area, a very loud explosion startled us. It turns out that the explosion was the discharge of a cannon (without ammunition) conducted by the local observatory to coordinate with the time of 12:00 noon.
HIKE 3: Table Mountain Aerial Cableway (lunch stop)
This hike was at the top of a magnificent geological formation known as Table Mountain, often referred to as one of the new 7 wonders of the world. It is referred to as Table Mountain because the peak does not culminate into a convergent point but rather it is a flattened surface resembling a table top.
Although it is possible to hike to the peak of Table Mountain, we chose the alternative form of transportation – aerial cableway. We all loaded into a cable car – capable of housing 65 individuals, and proceeded to the top of the mountain. The views were breathtaking and, because the floor of the cable car rotated – each passenger was able to enjoy the ride from different perspectives. We got to the top and, following lunch, proceeded to a hike of the Table Mountain National Park.
At the end of the day, we were all exhausted as it felt that we had hiked all around Cape Town. And judging from the Google Earth image tracking our expedition, it certainly looks like we did!
Day 4 (06/01/2016): Hands-on Lab Techniques /”Pachyderma Proxy”
On the agenda for today were several learning objectives including: learning the techniques needed to collect and properly wash a sediment sample from a core, how to take prepared sample and create a smear slide, a microscope activity involving prepared slides of protists, and an activity entitled, “Pachyderma Proxy.”
In order to create a smear slide, the first step is to collect and prep a sample. Samples were collected every 10 cm along a core, and then washed so that only the larger particles such as forams were retained. Forams are a group of calcareous protists that can be used to determine the age of the sediments as well as environmental conditions at the time they formed. These “bugs” as Dr. Krissek called them are an important tool that scientists use to help piece together the Earth’s geologic and climatologic past.
While the washed samples were drying in the drying oven, we were given prepared samples to create our own smear slides. We collected a small sample of sediment and smeared it around on a slide after adding a few drops of water, as shown in the accompanying figure. The next step was to dry the sample by placing it on a hot plate for a few minutes. After drying, a few drops of optical adhesive was added to the slide followed by the placement of a cover slip. The last step is to place the slide under UV light to allow the adhesive to cure.
After lunch, we were given prepared slides of diatoms, radiolarians, and forams. Under the microscope, we identified the different types of radiolarians and diatoms, and learned how to distinguish between benthic (organisms found on the seafloor) and planktic (drifting organisms usually found near the surface of the ocean) forams.
“Pachyderma Proxy” was an activity that allowed us to employ structural features of foram microfossils to indirectly determine the climate conditions in the Earth’s past at that location.
Day 5 (06/02/2016): Splicing, Dicing, and a Trip to the Aquarium
After dividing into two groups, we set off for the core lab. Our group learned how hard it is to splice cores to make a complete sediment record for a given sediment. Dr. Turner gave us three cores from two holes from the same site. Two cores from Hole B were sequential and the one core from Hole A was from the same general depth. We were told to make observations to try to find was of matching the Hole A core to the two Hole B cores in order to make one complete core from the three sample cores. The cores are taken close enough to each other that this is theoretically possible and, in fact, works most of the time. To assist in this task, we were given access to an instrument that uses color to determine the ages of a core.
Before lunch, we switched with the other group and joined Dr. Krissek to learn how to determine an age range for a particular point on a core using a microscope and smear slides that we created the day before. Our task was to use a nannofossil called discoasters that are found in the core sediment to determine age range. This is possible because discoasters evolved over time in shape. We had a key that showed which time periods in which they each existed. We used the smear slides we made the day before and determined that one sample was from the Eocene epoch making it the oldest and a second sample from the same site was slightly younger in the Oligocene epoch. The other two samples were much younger and came from the Miocene-Pliocene epochs.
After lunch, we stayed as one group and learned how to use Excel to graph data that helps find the points where cores can be spliced. Later that evening, it was off to the Two Oceans Aquarium which had phenomenal displays of ocean wildlife. We were treated to a Behind the Scenes tour of what it takes to maintain such an important facility.
Day 6 (06/03/2016): Studying Climate Change
The day started with the information provided by ocean core samples to determine climate changes in the past. We also explored a variety of other physical data such as ice core samples and other more complex computer and numerical data that pulls from multiple sources to better understand climate changes.
We are also excitedly planning out the student activities and other ways we will bring back our learnings about the ocean core, life at sea and more to our home institutions. Numerous ideas have been proposed, including an engineering design challenge involving students making their own ocean driller that must land on a precise piece of “ocean bed”, and a computer-aided design challenge to create a replica of an ocean core.
Day 7 (06/04/2016): Exploring Climate Cycles…and the Bridge
Drs. Krissek and Turner co-taught the morning session, with a focus on climate cycles. The morning activity explored cyclic climate change from the geologic record. Working in small groups, we discussed the data sets provided and studied methods used to analyze cycles. These methods included core data, carbon and oxygen isotopes, and the relationship between the Sun and Earth. This activity helped us to make connections to lab work we had done earlier in the week, giving us a greater understanding of the scientific research performed aboard the JR.
After lunch, we gathered our hard hats, safety glasses, and cameras for a tour of the Bridge. Mike Storms, Operations Superintendent, led the tour that started in the Engine room, where we learned about the operations that provide the ship with potable water, heating and cooling, and the waste systems. We then made our way to the Bridge, where Mike explained the dynamic positioning system, which keeps the ship stable during drilling. Next, the captain joined us on the Bridge and answered questions about navigating the JR.
Following the tour, we reconvened in the conference room to continue instruction from Drs. Krissek and Turner. The afternoon’s agenda included discussion about the PETM (Paleocene-Eocene Thermal Maximum) event. We analyzed more tables, graphs, proxy data, graphics, and text, followed by small-group work and whole-group discussions and explanations.
Day 8 (06/05/2016): Studying the Sands of Time
On our last full day aboard the ship, we began with a drive up the coast to Boulder’s Beach. Although we came to examine the physical processes representing the geological environment, we were instantly charmed with the local residents of this National Park, African penguins. Hundreds of penguins covered the beach and dune system, running in and out of the water, back to their nests to protect their chicks.
Within the dune system, we examined sand grains from the beach. Derived from local granite, wind brought these grains to the beach, where they were weathered and sorted through the back and forth motion of the waves.
Once back aboard the ship, we got to watch the crew in action during a fire drill. Hard hats in hand, we made our way to the dock, following protocols to make sure everyone was safe and sound. Back in the core lab, we examined sediment data collected by ANDRILL from the Ross Ice Shelf near East Antarctica. These samples provided an excellent opportunity to apply what we had learned this week. Using our observational skills and newly learned terminology, we identified siliceous and terrigenous sediments from the Antarctic region.
By taking a closer look at the presence of clasts within the matrix, we could come to new conclusions about the sediment. Smear slides revealed the presence of volcanic glass, in addition to biological materials. Applying Walther’s Law, we were able to explain layering patterns of clast-rich diamictite, well-sorted sands and gravels, clast-poor mudstone, and diatomite. These patterns help scientists to evaluate hypotheses about the history of ice sheets in the Antarctic.
Day 9 (06/06/2016): Homeward Bound
As the last day neared and we bid a fond farewell to new-found friends, colleagues and the JR, I walked away extremely appreciative of such an exceptional instructional experience. For those interested in learning more about the IODP, upcoming SOR offerings, or the vast array of instructional activities and opportunities available for educators, please visit the website: http://www.joidesresolution.org