North Star Geography - Eva Varga

This past week, I shared with you our discoveries while we were in the Galápagos in a five-day series titled, The Islands of the Galápagos. Today, I would like to share with you the wildlife of the Galapagos archipelago, while also showcasing the life zones and ecology of the islands.

Visitors to the islands notice that there are few species on the Galápagos archipelago. The geology of the islands, with the constant volcanic activity, creates a harsh, desert climate with very little rain and high temperatures so that only the higher slopes of the larger islands have enough rain to nourish a luxuriant growth of plants.

This, in turn, results in an environment that is very hostile for most animals that are found on the continent. Most of the islands are low and what little rain they get comes during a short rainy season, with the rest of the year being very dry. The amount of rain varies from one year to the next.

“The natural history of these islands is eminently curious, and well deserves attention… Considering the small size of these islands, we feel the more astonished at the number of their aboriginal beings, and at their confined range…Hence, both in space and time, we seem to be brought somewhat near to that great fact–that mystery of mysteries–the first appearance of new beings on this earth.” ~ Charles Darwin, The Voyage of the Beagle

“Eminently curious” well describes the natural history of the Galápagos, from its sere landscapes to its comical birdlife. For over 400 years this volcanic archipelago has both puzzled and stunned its visitors, and no aspect of the islands is as stunning as its wildlife. The ease of approach to the birds, iguanas, tortoises and other creatures of the Galápagos is due to their isolation from natural predators, a condition that first stirred Charles Darwin in 1835.

Eco-zones of the Galápagos

There are a total of seven zones within the archipelago housing a variety of plant life. Varying amounts of rainfall with altitude, and from island to island, have led to the formation of vegetation zones ranging from desert to lush cloud-forest.

Various plants and animals have adapted over the years to the conditions of the islands and in some cases the condition of the zone. Plantlife (or flora) is normally found in a specific zone and the animal life (fauna) dependent on those plants can be found in the same zone.

Coastal Zone

The lowest life zone on the island is the coastal zone. Those plants here can be divided into the Wet Coastal Zone (or Mangrove Zone) and the Dry Coastal Zone (beaches and high tide areas). Saltbush is found near most shores, where it forms a dense low shrubby tangle.

Mangroves are salt-tolerant trees and shrubs that thrive in shallow and muddy saltwater or brackish waters. In the Galápagos there are 4 varieties of Mangroves including the Black Mangrove, White Mangrove, Red Mangrove, and Button Mangrove.

Here most of our walks in the Galápagos took place — with the scuttle of the bright orange Sally lightfoot crabs underfoot, beneath the gaze and snort of the marine iguanas, to the barking of sea lions and the crashing of the surf off the shore. This is the environment we will remember when we look back on our time spent in the Galápagos.

Lowlands Zone

As an island slopes from the beach to an elevation of about 197 ft (60 m) elevation an arid desert like zone occurs. This region is home to the many Cacti that live in the Galápagos including the Prickly Pear Cactus, Lava Cactus, and Candelabra Cactus .

Vine plants also make their home here; the endemic lava morning glory and endemic passionflower can be found in this zone. At the top of the Arid Lowlands the silvery leafed Palo Santo Tree with its collection of lichens can be seen.

Transitional Zone

Rising up the island, plants become more frequent. In the Transition Zone plants from both the Arid Lowlands and the Upper Moist Zones occur. This zone is home to a variety of small trees or shrubs including the endemic Pega Pega Tree and the endemic Guaybillo, which produces a small white flower that develops into a fruit similar to its cousin the Guava.

“The distribution of the tenants of this archipelago would not be nearly so wonderful, if, for instance, one island had a mocking-thrush, and a second island some other quite distinct genus…. But it is the circumstance, that several of the islands possess their own species of tortoise, mocking-thrush, finches and numerous plants, these species having the same general habits, occupying analogous situations, and obviously filling the same place in the natural economy of this archipelago, that strikes me with wonder….” ~ Charles Darwin, Voyage of the Beagle

Scalesia Zone

The lowest of the “humid” zones, the Scalesia zone is named for the daisy tree that grows between 970-1970 ft (300 – 600 m) elevations. The Scalesia is one of the few trees in the Aster Family and grows to heights 16 – 50 ft (5-15 m) in height. Its trunk and branches are covered with moss and lichens. This area is humid and has the essence of being in a rainforest.

Scalesia Trees have been greatly reduced in numbers since humans arrived in the islands. With them came pigs and goats, which devour the young plants and feed on older plants. People also introduced the Guava, a plant whose dense growth patterns steals nutrients and eventually makes it impossible for competing plants to survive.

Brown Zone

An intermediate zone between the dense Scalesia forest and the Miconia shrubb vegetation, the Brown Zone is an open forest dominated by cat’s law, tournefortia pubescens, and aunistus ellipticus. Trees are heavily draped with epiphytes, mosses, livertorts and ferms, which give this zone a brown appearance during the dry season. However, on the islands with this elevation, this zone has disappeared because of colonization by man.

Miconia Zone

Above the Scalesia Zone at 1950 – 2300 ft (600-700 m) is the humid zone named for the Miconia shrub that once dominated this region. Miconia Robinsoniana grows to heights of 10-13 ft (3-4 m). The yellow or reddish shading on the edges of its leaves easily identify it.

The Miconia is endemic to the Galápagos, but since the arrival of man it has become the most endangered plant in the islands. Introduced cattle have grazed the Miconia into dangerously low levels.

Pampa Zone

On islands with elevations over 3000 ft (900 m ) the highest vegetation zone in the Galápagos can occur, the Fern-Sedge Zone or Pampa Zone . The appearance of this zone depends on the amount of moisture it receives. This region contains no true trees or shrubs. The tall Galápagos Tree Fern and Liverworts are commonly found in this zone.

Wildlife of the Galapagos *

BIRDS

Blue-footed booby (Sula nebouxii) ✓
Red-footed booby (Sula sula)
Nazca booby (Sula dactylatra) ✓
Waved albatross (Diomedia irrorata) ✓
Magnificent frigatebird (Fregata magnificens) ✓
Galapagos penguins (Spheniscus mendiculus) ✓
Lava heron (Butorides sundevalli) ✓
Great blue heron (Ardea herodias) ✓
Yellow-crowned night heron (Nyctanassa violacea)
Striated heron (Butorides striata) ✓
Brown pelican (Pelecanus occidentalis) ✓
Flightless Cormorant (Nannopterum harrisi) ✓
Lava gull (Larus fuligihosus) ✓
Flamingo (Phoenicopterus ruber)
Galapagos hawk (Buteo galapagoensis) ✓
Red-billed tropicbird (Phaethon aetheus) ✓
Storm petrels (Hydrobatidae) ✓
Swallow-tailed gulls (Creagrus furcatus) ✓
Galapagos mockingbird (Nesomimus parvulus) ✓
Cactus ground finch (Geospiza scandens) ✓
Warbler finch (Certhide a olivacea) ✓
Great egret (Ardea alba) ✓
Cattle egret (Bubulcus ibis) ✓
Galapagos rail (Laterallus spilonotus) ✓
Lava gull (Leucophaeus fuliginosus) ✓
Brown noddy (Anous stolidus) ✓
Galápagos dove (Zenaida galapagoensis) ✓
Darwin’s finches (Tanagers) ✓
American yellow warbler ✓
Galapagos pintail duck (Anas bahamensis galapagensis) ✓

REPTILES

Tortoise (Geochelone elephantopus) – fourteen subspecies ✓
Land iguana (Conolophus sp.) – two species ✓
Marine iguanas (Amblyrhynchus sp.) – seven subspecies ✓
Lava lizard (Tropidurus sp.) – seven species ✓
Gecko (Phillodactylus sp.) – seven species
Snake (Dromicus sp.)

MAMMALS

Sea lion (Zalophus californianus wollebacki) ✓
Fur seals (Arctocephalus galapagoensis)
Galápagos rice rat
Hoary bat
Eastern red bat

INVERTEBRATES

The Galápagos islands are also home to innumerable marine invertebrates. This very diverse group includes molluscs (e.g., shells and snails), marine annelids (e.g., segmented worms), echinoderms (e.g., sea urchins, sea stars, and sea cucumbers), cnidarians (e.g., corals and gorgonians), sponges, and many others. Some of the more notable species we observed include:

Sally Lightfoot Crab ✓
Sea Cucumbers ✓
Chocolate Chip Star ✓
Blue Sea Star ✓
Galapagos Carpenter Bee ✓
Large Painted Locust ✓
Galapagos Scorpion ✓

* checkmarks indicate the animals we observed

If you would like to further explore the Galápagos from the comfort of your home or if you are planning to visit yourself, my multidisciplinary unit study, Galápagos Across the Curriculum, provides ample opportunity for kids to explore the diversity and remarkable history of the islands through a variety of hands-on science activities and projects.

This past week, I have been sharing with you our discoveries while we were in the Galápagos in a series titled, The Islands of the Galápagos. The strange beauty and attraction of these volcanic upwellings wove their mystery around us just as they have others who have visited since the archipelago was first discovered in 1525 by the Bishop of Panama, Tomas de Berlanga.

Today, I would like to expand upon the geology and geography of the Galápagos archipelago and share with you some of the resources that aided in our understanding of these enchanted islands.

The Galápagos archipelago consists of 18 main islands, 3 smaller islands, and 107 rocks and islets. The islands are located at the Galapagos Triple Junction – a confluence of three tectonic plates, the Cocos Plate, the Nazca Plate (which is moving east/southeast), and the South American Plate. It is also atop the Galapagos hotspot, a place where the Earth’s crust is being melted from below by a mantle plume, creating volcanoes.

Geology of the Galápagos

Geology (from the Greek γῆ, gē, i.e. “earth” and -λoγία, -logia, i.e. “study of, discourse”) is a field of science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change.

Plate Tectonics

Using our North Star Geography program as our guide, we learned about plate tectonics prior to our departure. There are three types of boundaries between tectonic plates:

Divergent Boundaries – where two plates are moving away from each other
Convergent Boundaries – where two plates push up against one another
Transform Boundaries – where two plates move horizontally, slipping past each other in opposite directions

After reading the chapter, we created edible models of the boundary types in STEM Club (see my earlier post, Plate Tectonics, for lesson details). This was a great activity and the kids really enjoyed manipulating the earth’s plates (i.e. graham crackers).

North-Star-Geography — As a Brand Ambassador for Bright Ideas Press we have received a complimentary copy of North Star Geography in exchange for our honest insights about how this program is working in real life with our family.

Dynamic Plate Boundaries

The lithosphere is broken up into 15 major plates, which move with respect to one and other. Mid-oceans ridges, a type of divergent boundary, are located at the edges of plates moving away from one and other on the ocean floor. One such mid-ocean ridge, the Galápagos Spreading Center, is located just north of the archipelago.

Mid-ocean ridges are often offset by fracture zones or transform faults. A major transform fault is located just north of the islands.

galapagosspreadingcenter Subduction zones occur where plates collide. A major subduction zone is located where the Nazca and Cocos Plates are subducting beneath the South American and Carribean plates. Subduction zones are marked by deep trenches and overlying chains of volcanoes (the Andes, for example).

Mantle Plume

The Galápagos Islands are one of most active oceanic volcano areas in the world. Like many oceanic islands, the Galapagos are thought to be the product of a mantle plume – columns of hot rock that rise from deep within the Earth. These plumes rise because they are hotter and therefore less dense, than the surrounding rock.

As a lithospheric plate moves over a mantle plume, a chain of volcanoes is created. The volcanoes get older in the direction of plate motion. The Galápagos Islands are located on the Nazca Plate, which is moving east-southeast. Thus, the islands get older to the south-southeast and it has produced a chain of seamounts known as the Carnegie Ridge.

A second seamount chain, the Cocos Ridge, extends northeast from the Galápagos Spreading Center. Thus a chain of volcanos was produced on both the Cocos and Nazca plates.

Geography of the Galápagos

Geography (from Greek γεωγραφία, geographia, lit. “earth description”) is a field of science dedicated to the study of the lands, the features, the inhabitants, and the phenomena of the Earth.

Volcanoes

In our North Star Geography text, we also learned that there are a number of different kinds of volcanoes. We observed two distinct types of volcanoes in the Galapagos. In the west, on the islands of Isabela and Fernandina, large volcanoes with an “inverted soup-bowl” morphology and deep calderas occur. In the east, smaller shield volcanos with gentler slopes occur.

One of the activities suggested in the North Star Geography activity guide, is to make a topographical salt dough or cookie dough map. The Galápagos islands were the perfect “model” for this activity.

In addition to the salt dough map, the kids enjoyed creating an accordion-style picture dictionary as we were traveling. You can download this free printable, Geography Picture Dictionary, for your personal use. It is a great supplement for North Star Geography. Children can sketch the geography specific to a region (as we did) or use it in a more general sense.

Craters & Sink Holes

The twin craters of Los Gemelos (one of which is pictured above) are a highlight of the Santa Cruz highlands. Though a lesser know attraction, Los Gemelos, are actually sink holes, not volcanic craters, on the highest part of Santa Cruz. These depressions were formed by collapsing underground lava tunnels.

Upland Forests

This region also boasts of a beautiful Scalasia forest with trees covered by many epiphytes. In recent years, however, some plants have been introduced that are invading the Scalesia pedunculata forest rapidly. What was interesting here was that in addition to the Scalasia, cacti were also present (though more abundant in the lowlands).

In contrast to the dry coastal lowlands, the highlands are covered by mist in the garua (foggy) season and receive thus much more moisture and support a more luxuriant vegetation.

My son has been fascinated with planes, ships, and trains for as long as we can remember. What boy isn’t, right? He has expressed interest in working for Maersk and even has a blog where he writes about his passions, A Boy & His Trains.

When we were in the Galápagos, he would often wake before the rest of us and wander about the ship on his own accord. If he wasn’t in his cabin or on deck with one of the other passengers (he really connected with Gary – an older gentleman from Alaska who shared many similar interests), he could be found on the bridge with the Captain.

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OhCaptain

I loved that he had the freedom to explore the Evolution and that the crew was willing to take him under their wing. He learned a lot about navigation on our voyage. I was sure to expand on this real life experience with the help of North Star Geography.

Navigation

Explorers have always used the night skies to measure latitude by measuring how many degrees above the horizon the North Star (Polaris) appeared. Below the equator, Polaris is no longer visible, and the constellation known as the Southern Cross must be used instead.

Knowing your position and direction are key parts of navigation. It is also important to establish your route. Which route is best? Where do you turn?

As a Brand Ambassador for Bright Ideas Press we have received a complimentary copy of North Star Geography in exchange for our honest insights about how this program is working in real life with our family.

Tools of the Trade

Tools for measuring position have changed dramatically since the first explorers began traversing the globe. While the compass has not changed dramatically, many other tools have been invented. We loved reading about the tools early explorers used to navigate in North Star Geography and have enjoyed using some of these ourselves.

Compass: a good orienteering compass is important for learning and using a compass. Compass Sighting, or triangulation, uses two points to determine your location using a compass, a map, and a pencil. We use a compass often – we love the sport of orienteering.

Marine Astrolabe: The original tool for mariners, the astrolabe was a circle, held by a ring at the top, with a movable sight. The navigator would hold the instrument by the ring to determine the angle of a star relative to the horizon. The navigator would often sight multiple stars and consult reference books or Star Charts for accuracy.

Quadrant: Similar to a Marine Astrolabe but only a quarter of a circle and with a longer sight, allowing for greater accuracy.

Sextant and Octant (1700s): Instruments similar to a Quadrant but smaller (1/6 and 1/8 of a circle) that relied on two sights – one for the horizon and another for the sun or stars. Mirrors were used so that someone could see both objects at the same time.

Radar: A modern device that uses radio waves bounced off distant objects and calculates the time it takes them to return to calculate distance.

Sonar: Another modern device that works the same way underwater, but using sound waves instead of radio. We have utilized sonar on a few occasions – while fishing with family on the North Sea, while enjoying water sports on Shasta Lake, and most recently in the Galápagos. It is fun to see what the surface looks like below the water.

Topographic Maps: In modern mapping, a topographic map is a type of map characterized by large-scale detail and quantitative representation of relief, using contour lines to show elevations and landforms. We love looking at topographic maps and have even used them to create 3-dimensional models, Build Geography Skills with Topographic Maps.

Other tools used by navigators include a Chip Log (piece of wood tied to a rope with knots at regular intervals), GPS, and Binoculars.

Bring it Home

Map the sky: Learn to recognize constellations through the seasons and how navigators used the stars to stay on course.

Use a sextant to sight the north star to measure your latitude. You can determine this using the maximum height of the sun during the day and the maximum height of the north star at night. It is easiest to do this on a beach (large lake or ocean) where you can site off the water, but you can do it in your backyard using a level as well. The trick is finding a sextant! See How a Sextant Works for more information.

Navigation where you are: How was your state or area explored? Here in California, Sir Francis Drake is linked to the earliest exploration here, though some historians dispute he ever landed here. Who is a famous explorer where you live? Study more about him. Where was he from? Who traveled with him? What navigational tools did he have at the time?

Determine Magnetic Declination: This is the difference between magnetic north (or south) on your compass and true north (south). This will vary depending on where you are and over time. You can usually find the magnetic declination on USGS maps for wilderness or navigational use. We have one of some local forest lands which include the magnetic declination as part of the map’s key. If you can’t find out specifically what it is where you are, just investigate what it means and how to find out what it is and why it’s important.

I love when we can learn subjects by using real life examples, like using maps to work on geography. Whenever we travel, our first go to resource is a simple map, it helps us to get our bearings and to visualize the larger picture of how everything is connected.

My children have developed map skills to help with our vacation planning and to successfully find their way around the place we are visiting. To give you some ideas for learning on vacation, here are a few ways we reinforced map skills during our recent trip to South America.

To help us learn more about the many wonderful sites we would be visiting, we first used Google Earth to see the geological features such as the Andes Mountains where the Nazca Plate is sub-ducting under the South American Plate. We also viewed the Galápagos Islands and viewed the hotspot where new islands are forming.

We discussed the geological processes that are shaping the islands and how the plants and animals that live there are specifically adapted to life in this harsh environment. I shared with them the definition for endemic species and we talked about the species we were most looking forward to seeing ourselves.

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usingmaps

To add some learning to your vacation, use your guide maps/road maps as a teaching tool. Show your kids how to use them and then encourage them to navigate while sightseeing. They’ll love it and won’t realize that they’re learning too!

A map is a visual representation of a place or of information about a place. The place could be small, like a room, or larger, like a house, neighborhood, city, state, country, planet, solar system, or galaxy. – North Star Geography, Lesson 1

As a Brand Ambassador for Bright Ideas Press we have received a complimentary copy of North Star Geography in exchange for our honest insights about how this program is working in real life with our family.

While sightseeing in the Galápagos, Cristina – our interpretive guide, pulled out a bandana map at each island we visited to point out each of the surrounding islands. In time, the kids were able to correctly identify each of the islands themselves not only by their profile but by their geographical orientation as well. They were so captivated by this experience that a bandana map was their top souvenir choice.

Now that we are home, the kids are looking forward to creating an interactive map with My Maps, one of many mapping tools provided by Google Maps. They have already begun to flag the photos they wish to embed and have begun to brainstorm their storyline.

Tips for building map skills:

Help your children find maps before you depart on vacation. Take some time to look over them prior to departure or while en route to get the “lay of the land” before you arrive.
Identify the map’s title, legend, compass rose, and scale.
Help your child identify two points on the map and ask them to determine the best path to travel between the locations.
Document your travels using a map. At the end of each day, highlight the route you traveled and mark the things you did and saw along the way. Consider using My Maps to create an interactive map that you can share with friends and family.

Bright Ideas Press has created a survey to see what kinds of geography products homeschool moms most want. They need their feedback no later than Wednesday, Nov. 26.

As a thank you, you will receive a freebie code for an audio workshop at the end of the survey. It’s called History and Geography Through Literature, a $5.00 value.