Coincidence in the Ring of Fire?

EarthView students know that the island nation of Indonesia -- the world's fourth-most populous country -- is located on the Pacific Ring of Fire. 

The eruption and the earthquake that triggered the tsunami this week occurred 800 miles apart, affecting two separate islands -- Java and Sumatra. They may be related, as have similarly distant events in the past, such as an Alaska earthquake and geyser activity in Yellowstone, Wyoming. Indonesia is the most tectonically active place on Earth, however, so it will be some time before a connection can be proven or discounted.

Learn more about this week's tragedies and the possible connections from National Geographic magazine.

National Geographic photo of damage from 2004 tsunami

Gordon Mitchell School, East Bridgewater -- October 22

42° 01' 50" N
70° 56' 43" W
Learn more about Lat/Long

The EarthView team is delighted to be returning to the Gordon W. Mitchell School in neighboring East Bridgewater, Massachusetts, which the team last visited in 2009. In fact, two Mitchell students are close family friends of team member Dr. Hayes-Bohanan.

The school is located very close to a site known as Sachem Rock, where the original conveyance of land from the Wampanoag Indians to Miles Standish in 1651. This land became the town of Bridgewater in 1656, and that town was eventually divided into what we now know as seven different cities and towns. In some ways, this was the beginning of the westward expansion of what would become the United States.

During the visit, the team was accompanied by Kiado Cruz, a farmer and activist from Chiapas, Mexico, and his team from Witness for Peace. They gave a presentation on the importance of local agriculture at Bridgewater State University on October 21 as part of a New England tour of schools, churches, and civic organizations. Although Kiado, Nikky, and Susan did not have a chance to visit with Mitchell students, they did have an opportunity to see the world from the inside, and to contemplate their own important work in a global context.

Drying Lakes

Lake Chad images (1972 and 1987)
 as posted Waterless on the Town Square blog

EarthView is a terrific learning tool, whether viewed from inside or out. During today's program at the Ahern Middle School, a student looking at north-central Africa from outside asked about the body of water surrounded by dry land. What she was noticing was Lake Chad, which was once the sixth-largest lake in the world but had already lost a considerable amount of its surface area by the time EarthView was painted in the 1990s. In that sense it is much like the Aral Sea, which long ago surrendered its status as the world's fourth-largest lake, and which the EarthView artist represented with a similar, broad fringe of dry land.

Both lakes are found in arid or semi-arid lands, and are shared by multiple countries -- Nigeria, Niger, Chad, and Cameroon in the first case and Kazakhstan and Uzbekistan in the latter. Moreover, in the case of the Aral Sea, lands in four additional countries contributed directly to the drainage area of the sea.

Image from the Fire Earth blog

Growing or shrinking lakes represent shifts in the water balance for the watersheds (also known as drainage basins) in which they are found. Lakes can shrink as a result of water use that exceeds rainfall in the basin as a whole. This in turn can affect habitat in and near the lake, the availability of irrigation or drinking water, and even the regional climate.

Both of these shrinking lakes are excellent examples of the use of satellite images to monitor lakes. The  United State Geological Survey  (USGS) includes both Lake Chad and the Aral Sea in its EarthShot series, which documents many other examples of the uses of remote sensing. The Visualizing Earth project at UC-San Diego has a similar Aral Sea page that -- like the EarthShots pages -- allows users to move between satellite and ground-level images.

For decades to come, Lake Chad and the Aral Sea will remain reminders of how seriously humans can damage the natural environments on which we depend. Despite the bad news, some positive steps are being taken: international bodies are working together to protect the wetlands of Lake Chad and a new dam is helping to increase the flow of water to the Aral Sea. People in many countries have much more to do, however, if these lakes are to be fully restored!

Ahern Middle School - Foxborough - October 15

42° 4' 27" N
71° 14' 18" W
Learn more about Lat/Long
The John J. Ahern Middle School in Foxborough is hosting the EarthView team for the third time in the program's three years. A lot has happened with EarthView and with the Geography Department that runs the program  since the first visit in 2008.
For example, the department is no longer part of Bridgewater State College -- it is now part of Bridgewater State UNIVERSITY, a teaching university that will continue to serve the region. Second, the department -- formerly in the School of Arts & Sciences -- is now part of the university's new School of Science & Mathematics.  Geography is both a social and a physical science, connected to the other so-called STEM disciplines.
The EarthView team is particularly interested to learn that Ahern will soon have a family math night. We will be sharing ideas with Ahern teachers about ways to include geographic fun in that event!
To learn more about what EarthView has achieved over the past three years and what still lies ahead, the team invites you to scroll through the blog -- which now has close to 100 articles about school visits, geographic education, and some fascinating stories of our planet!

Circle of Illumination

WORLD SUNLIGHT MAP

In the hallway outside the Geography Department office at Bridgewater State University is a fascinating device known as Geochron. Manufactured decades ago, it is a combination map and clock that is configured so that it always represents the areas of the earth in sunlight and darkness. At all times, exactly one half of the earth is illuminated by the sun, though cloud cover can affect how much reaches the surface and latitude can influence its intensity. The 50 percent in sunlight is known as the circle of illumination, because the boundary between sunlight and darkness forms a circle.

On the equinoxes, the circle of illumination intersects both the north and south poles, but during the rest of the year, the circle appears tilted first one way and then another, as the earth orbits the sun at a constant 23.5-degree angle. During this orbit, the apparent position of the sun changes steadily, and it appears directly overhead at only one place at a time on the planet. That location is known as the sub-solar point, and it oscillates from the Tropic of Cancer on the summer solstice to the Tropic of Capricorn on the winter solstice (as defined in the northern hemisphere -- people in the south use the opposite terminology).

On the original, mechanical Geochron, a small dot represents the single place on earth -- always in the tropics -- where the sun appears to be directly overhead. Of course, there is only one such point at any time, known as the sub-solar point because it appears to be under the sun.It moves from the Tropic of Cancer on our summer solstice to the Tropic of Cancer on our winter solstice, crossing the equator on the equinoxes.

Two digital versions of the GeoChron are readily available online. The World Sunlight Map shown above also represents current cloud cover and is available in several different projections. The NIST version from the National Institute of Standards is accompanied by the current, official time as used for U.S. Government purposes. (Be sure to adjust the time zone or display options if necessary.)

With parental permission, it is also now possible to install a miniature version of the GeoChron as a desktop gadget on your computer, allowing you to track the sun at all times.

We invite EarthView participants to view the mechanical GeoChron in our geography department, in order to see the circle of illumination in more detail and to marvel at the clever, compact design. On the mechanical version, it is also possible to see how the sun's noon position advances and retreats through the year not only by latitude but also by longitude, tracing the figure-eight shape of the analemma.

World Daylight Clock on Your Desktop

The circle of illumination always lights half of the earth's surface, with the other half left in darkness and a thin band of twilight in between. You can check the digital version of GeoChron on the EarthView blog throughout the year to learn how the illuminated area changes through the seasons. You can also -- with parental permission -- install the World Daylight Clock (a Google Gadget) on your desktop to watch the progress of the sun minute-by-minute.

I captured the image above just a couple minutes ago, while writing this article. It shows that my home in Bridgewater is about to rotate into the circle of illumination, and indeed it is twighlight outside my window.

Spofford Pond School, Boxford -- September 24

Spofford Pond School

42°41'46"N 

71°01'02"W
(Learn more about Lat/Long for ideas that combine math and geography learning. For example, this is the farthest north we have taken EarthView; an article in the archives for November 2009 indicates the one time we came closest to this latitude -- what college was the site of that visit?)

Most EarthView programs are in Southeastern Massachusetts, relatively close to EarthView's home base at Bridgewater State University.

As geographers, we love to travel to new places, and most of the team has spent little if any time in Boxford prior to this visit. Also, our goal is to improve geographic education throughout Massachusetts, so we are delighted to have our first North Shore school visit.

In exploring the geography of Boxford, we learned that it is facing an environmental problem that some might find surprising: the margin between forest and growing suburbs includes ideal conditions for beavers. Adorable as beavers may be, they create an unusual set of problems for suburban homeowners. The town web site includes a report on beaver encroachment and what to do about it.

The EarthView team learned some interesting news about geographic research from Spofford Pond teacher Ms. Sorensen. As reported by Discovery, computer models have provided a plausible explanation for the biblical story of the parting of the Red Sea.

East Middle School in Braintree - Sept 17

42°13'15"N 

70°59'23"W
(How far is this from South Middle School? Learn more about Lat/Long)

The EarthView team is delighted to continue the new school year with a return to Braintree. We encountered a lot of great geography students last week at South Middle School. We have provided the latitude and longitude of each school (as we do for all EarthView programs).

Here is a challenge: How far apart are the schools? They would be in the same little red dot of our laser pointer on EarthView, but there is some distance between them. It be measured in feet, miles, meters, inches, or kilometers along the road or along a straight line. It can also be measured in degrees, minutes, and seconds on the globe!

South Middle School in Braintree -- September 10

42°11'02"N 

70°59'53"W
(Learn more about Lat/Long) 

After quite an exciting summer of special appearances (see recent blog posts below) the EarthView Team is delighted to be reunited for the start of our third school year. Close to 20,000 students and community members have seen EarthView in the past two years, and we look forward to bringing our program to thousands more this year -- each in small groups that have the special experience of seeing the earth from the inside out!

We started the year with two programs in Braintree, the first of which was at South Middle School, where Mrs. Drayer teaches geography through the Olympics! We also learned that Mrs. Drayer and EarthView team member are both proud UMBC Retrievers!

Bridgewater State University

41°59'15"N 

70°58'12"W

(Kelly Gymnasium)

After 170 years as a Normal School, Teachers' College, State College -- with a few other titles over the years as well -- the home of EarthView is now the Geography Department at Bridgewater State University, the largest institution in the new Massachusetts State University system.

Opening Day this year included a visit from Gov. Deval Patrick, a fly-over courtesy of the BSU aviation program, and of course an EarthView exhibition! We were honored that our visiting librarian-scholar from Cambodia took the time to visit EarthView; having seen the Mapparium in Boston earlier in her visit, she will return to Cambodia with two very memorable geography experiences!

BSU Library Assistant Joan Luiz, Pannasastra University Librarian Vanna Sok, and EarthView Team member James Hayes-Bohanan pose directly "south" of Cambodia on BSU Opening Day.

BSU relies on energetic, cheerful, and well-informed Orientation Leaders to welcome each class to campus. This year, the OLs were enthusiastic participants in their own special orientation to the planet! One of the OLs is actually a BSU geography major. (She is shown above, in the red shirt.)

Latitude/Longitude Converters

Geographers and other scientists use latitude and longitude to identify places on earth reliably and precisely. Every location on earth has a unique combination of latitude (north or south of the equator) and longitude (east or west of the Prime Meridian). Geographer Matt Rosenberg explains these concepts in more detail in his article Latitude and Longitude: Discover the Secrets of Parallels and Meridians.

Latitude and longitude are each expressed as degrees or fractions of degrees. At the equator, a whole degree can be used to locate a place to within a mile or so -- a suitable level of precision for locating a city, for example. A degree comprises 60 minutes, so that a latitude or longitude expressed in degrees and minutes is precise to roughly 100 feet, which is suitable for a lot of purposes, such as finding a house. Fractions of an arc minute are known as seconds, and again there are 60 to each minute. At the equator, coordinates expressed as degrees, minutes and seconds would be precise within a couple of feet. Fractions of a second might be used for even more precise work, such as the location of property boundaries, the corners of a building, or the location of a well. (The caveat "at the equator" is used above because the surface length of a degree of latitude changes slightly from the equator to the poles because of the oblateness of the earth's shape, and the length of a degree of longitude changes dramatically, down to zero at the poles, because of the convergence of the lines there.)

Followers of this blog may already be familiar with the latitude/longitude lookup utility created by Steve Morse, which allows users to look up addresses and find latitudes and longitudes. What is especially useful about this site is that it does not draw on just one source. It uses various mapping web sites, showing that although each site is precise to the equivalent of inches or millimeters, they are only as accurate as the datasets upon which they are based. For any given address, users may find small or large differences, depending on how large a property is, and how each database treats its proximity to nearby roads.

For various reasons, it is often useful to express latitude and longitude as decimal fractions of degrees, rather than minutes and seconds. This is particularly true if distance or area calculations are being made on the basis of the coordinates. Geographers usually prefer the conventional terms, however. Conversion from one to the other is relatively simple, but it can be tedious. For this reason, the conversion utility from the FCC is particularly helpful. It allows users to enter coordinates in either format (d-m-s or decimal) and convert easily to the other. Another interesting utility allows the distance between two points to be calculated from their respective coordinates.

Have you ever heard that if you could dig a really deep hole, you could get to China? From locations in North America, this would not be the case, even if digging such a whole were possible. Geographers can use latitude and longitude to make a simple calculation of where such a journey would end, by finding the antipode. In fact, for most locations on land, the antipode is in a body of water.

"Earth Sandwich" enthusiasts have made a fun geographic project of marking antipodes by making 8,000-mile-thick sandwiches of the earth, with a piece of toast carefully located on opposite sides of the planet at the same time. A similar hobby is the marking of degree confluence points in the geodetic grid, one of which is located very close to EarthView's home in Bridgewater, Massachusetts.

Photos from Summer of Science program

EarthView team members Dr. Domingo and Dr. Hayes-Bohanan thoroughly enjoyed our visit to the Massachusetts Maritime Academy on July 9 to be part of the Summer of Science kick-off event. (Our team also included geography alumna Monique Buckley, educator and photographer extraordinaire and winner of the Rao Scholarship.) We enjoyed the company of faculty, staff, and students from all six CONNECT campuses who are bringing very impressive Science, Technology, Engineering & Math (STEM) outreach programs to the young people of southeastern Massachusetts. It was great to see so many committed colleagues and students from public higher education contributing to the development of human capital of our region from early childhood through post-graduate education.

We also had occasion to meet some of the area children who participate in the programs, and the CONNECT leaders and other officials who advocate tirelessly for public higher education in our Commonwealth. We had time to take a few photos of our own, but we know other media were present, and we hope to provide links to additional coverage in the next few days.

As EarthView fans know, we will take our giant globe anywhere there is an audience. For this occasion, we rose to a unique challenge, and safely inflated EarthView among the model engines in a mechanical teaching bay.

We were delighted to continue our discussion of K-16 geography education with our own Dr. Dana Mohler-Faria (r), President of Bridgewater State College and with Massachusetts Secretary of Education Paul Reville (2nd from left).

We were also pleased to show EarthView to Dr. Jean MacCormack, Chancellor of the University of Massachusetts-Dartmouth and Admiral Richard Gurnon, President of Mass Maritime and host of this lovely event.