April 17, 2005
Social Studies Activity 2 - What's in a Name?
When Jason and Lourdes depart Darwin, Australia for Dili, East Timor in pedal boat Moksha, you will find that the sea-going journey of this expedition has a language all of its own. The following are some commonly used nautical terms that you may find in their updates.
Nautical Glossary :
Aft, After
Toward the stern (rear) of the boat.
Aground
When a boat is in water too shallow for it to float in, i.e: the boat’s bottom is resting on the ground.
Anemometer
A device that measures wind velocity.
Astern
Toward the stern of a vessel, or behind the boat.
Bail
To remove water from a boat, as with a bucket or a pump.
Ballast
Weight at the bottom of the boat to help keep it stable. Ballast can be placed inside the hull of the boat or externally in a keel.
Bar
A region of shallow water usually made of sand or mud.
Berth
(1) a place for a person to sleep. (2) a place where the ship can be secured. (3) a safe and cautious distance, such as “We gave the shark a wide berth.”
Bow: The front of the boat.
Breakers
A wave that approaches shallow water, causing the wave height to exceed the depth of the water it is in, in effect tripping it. The wave changes from a smooth surge in the water to a cresting wave with water tumbling down the front of it.
Cardinal points
The points of North, South, East and West as marked on a compass rose.
Celestial navigation
A method of using the stars, sun and moon to determine one’s position. Position is determined by measuring the apparent altitude of one of these objects above the horizon using a sextant and recording the times of these sightings with an accurate clock. That information is then used with tables in the Nautical Almanac to determine one’s position.
Channel
A navigable route on a waterway, usually marked by buoys. Channels are similar to roads where the water is known to be deep enough for ships or boats to sail without running aground.
Compass rose
A circle on a chart indicating the direction of geographic north and sometimes also magnetic north.
Coordinated Universal Time (UTC)
The international time standard. It is the current term for what was commonly referred to as Greenwich Meridian Time (GMT). Zero (0) hours UTC is midnight in Greenwich England, which lies on the zero longitudinal meridian. Universal time is based on a 24 hour clock, therefore, afternoon hours such as 4 p.m. UTC are expressed as 16:00 UTC (sixteen hours, zero minutes).
Current
The movement of water, due to tides, river movement and circular currents caused by the motion of the earth.
Dead reckoning
A method of determining position by making an educated guess based on last known position, speed and currents.
Gale : A storm with a wind speed between 34 to 40 knots.
Global Positioning System
GPS for short. A system of satellites that allows one’s position to be calculated with great accuracy by the use of an electronic receiver.
Greenwich Meridian Time (GMT)
A time standard that is not affected by time zones or seasons. Now called Coordinated Universal Time (UTC).
Heavy seas
When the water has large or breaking waves in stormy conditions.
High tide
The point of a tide when the water is the highest. The opposite of low tide.
Hull
The main structural body of the boat. The part that keeps the water out of the boat.
Knot
(1) a speed of one nautical mile per hour. (2) a method of attaching a rope or line to itself, another line or a fitting.
League: Three nautical miles.
Longitude
Imaginary lines drawn through the north and south poles on the globe used to measure distance east and west. Greenwich England is designated as 0° with other distances being measured in degrees east and west of Greenwich.
Magnetic north
The direction to which a compass points. Magnetic north differs from true north because the magnetic fields of the planet are not exactly in line with the north and south poles.
Nautical mile
Distance at sea is measured in nautical miles, which are about 6067.12 feet, 1.15 statute miles or exactly 1852 meters. Nautical miles have the unique property that a minute of latitude is equal to one nautical mile (there is a slight error because the earth is not perfectly round.) Measurement of speed is done in knots where one knot equals one nautical mile per hour. A statute mile is used to measure distances on land in the United states and is 5280 feet.
Parallels : Lines of latitude
Port
(1) the left side of the boat from the perspective of a person at the stern of the boat and looking toward the bow. The opposite of starboard.
Starboard
The right side of the boat from the perspective of a person at the stern of the boat and looking toward the bow.
Stern
The aft part of a boat. The back of the boat.
Yaw
Swinging off course, usually in heavy seas. The bow moves toward one side of the intended course.
Zulu
Used to indicated times measured in Coordinated Universal Time, a successor to Greenwich Mean Time. A time standard that is not affected by time zones or seasons.
Lesson Activities:
Materials:
blank paper
clip art depicting boats, harbors, maps, globes (these pictures will be used to create a 'pictionary' of descriptions of the nautical terms
colored pencils
Preparation:
Divide your social studies group into sections of a minimum of two students.
Select words from the nautical glossary that your group would like to research.
Procedure:
of your nautical terms illustrate each one, making sure that you have labeled items in the pictures correctly.
Your definitions and pictures should accurately portray the meaning of each term selected.
Informational Links:
Posted by april at 2:52 AM | Comments (0)
April 2, 2005
Social Studies Activity 1 - Leapin' Lizards
Crocodiles are survivors from the dinosaur age. A crocodile then looked very much like it does now. Crocodiles belong to a reptile family that did not become extinct like most dinosaurs 65 million years ago.
The features of the crocodile today are very similar to what they were 15 million years ago. A crocodile's armor-plated skin is made up of tough scales called scutes. These are reinforced from bony plates just below the surface.
Prehistoric crocodiles were giants, some up to 40 feet (13 meters) long! They preyed on other reptiles, including small dinosaurs. Other prehistoric crocodiles were as small as lizards.
Crocodiles have been honored throughout history. Egyptians in the town of Crocodilopolis had a crocodile god. The ancient Egyptian god of water, Sobek, was in the shape of a crocodile. Alligators, from the same reptilian family as crocodiles, got their name from 'el lagarto,' the Spanish word for lizard!
The estuarine (saltwater) crocodile from Australia, Indonesia, and Southeast Asia is the biggest of all crocs! This massive croc is the only one to swim in the sea. They live in estuaries along the coast and can grow BIGGGGG! The largest saltwater crocodile on record was 27 feet (9 meters) in length and weighed two tons!
With the coming of the European colonists, crocodile habitats became crowded with humans. Both enjoyed the living conditions along the Australian coastal areas. Unfortunately, they couldn't cohabitate as both were creating a problem for the other! No only did crocodiles hunt their prey from the rivers as animals came to drink, they also have the ability to leap as much as 9 feet (3 meters) out of the water after a meal! Crocs began feeding on livestock and then humans nearly hunted the crocs out of existence.
In 1972, crocodile hunting was banned in Australia. It is believed that around 270,000 saltwater crocodile skins and between 200,000 and 300,000 freshwater crocodile skins were exported from Australia before the ban. To meet consumer needs for their meat and their skins, crocodile farms now raise crocs. Poaching of these reptiles has become less of a problem. The croc farms have also become a major tourist attraction, especially at feeding time!
Things to Do With this Lesson:
Vocabulary:
export
poacher
cohabitate
estuary
prey
ban
Materials:
Preparation:
Procedure:
Use these links to help you research:
Crocodiles.com>
Aborginal Crocs
Marine Bio
Species List
Alligators & Crocs
Posted by april at 4:31 PM | Comments (3)