Marshall Islands stick chart
Encyclopedia
Stick charts were made and used by the Marshallese to navigate the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 by canoe
Canoe
A canoe or Canadian canoe is a small narrow boat, typically human-powered, though it may also be powered by sails or small electric or gas motors. Canoes are usually pointed at both bow and stern and are normally open on top, but can be decked over A canoe (North American English) or Canadian...

 off the coast of the Marshall Islands
Marshall Islands
The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...

. The charts represented major ocean swell
Swell (ocean)
A swell, in the context of an ocean, sea or lake, is a series surface gravity waves that is not generated by the local wind. Swell waves often have a long wavelength but this varies with the size of the water body, e.g. rarely more than 150 m in the Mediterranean, and from event to event, with...

 patterns and the ways the islands disrupted those patterns, typically determined by sensing disruptions in ocean swells by islands during sea navigation. Stick charts were typically made from the midribs of coconut fronds tied together to form an open framework. Island locations were represented by shells tied to the framework, or by the lashed junction of two or more sticks. The threads represented prevailing ocean surface wave
Ocean surface wave
In fluid dynamics, wind waves or, more precisely, wind-generated waves are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They usually result from the wind blowing over a vast enough stretch of fluid surface. Waves in the...

-crests and directions they took as they approached islands and met other similar wave-crests formed by the ebb and flow of breakers. Individual charts varied so much in form and interpretation that the individual navigator who made the chart was the only person who could fully interpret and use it. Use of stick charts and navigation by swells apparently ended after World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, when new electronic technologies made navigation more accessible, and travel between islands by canoe lessened.

Significance of stick charts to the history of cartography

The stick charts are a significant contribution to the history of cartography
Cartography
Cartography is the study and practice of making maps. Combining science, aesthetics, and technique, cartography builds on the premise that reality can be modeled in ways that communicate spatial information effectively.The fundamental problems of traditional cartography are to:*Set the map's...

 because they represent a system of map
Map
A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....

ping ocean swell
Ocean Swell
Ocean Swell was a British Thoroughbred racehorse and sire. In a career that lasted from 1943 to 1945 he ran fifteen times and won six races. As a three-year-old 1944 he won the New Derby, a wartime substitute for the Epsom Derby run at Newmarket...

s, which was never before accomplished. They also use different materials from those common in other parts of the world. They are an indication that ancient maps
MAPS
Maps is the plural of map, a visual representation of an area.As an acronym, MAPS may refer to:* Mail Abuse Prevention System, an organisation that provides anti-spam support...

 may have looked very different, and encoded different features from the earth, than the maps we use today.

The charts, unlike traditional maps
MAPS
Maps is the plural of map, a visual representation of an area.As an acronym, MAPS may refer to:* Mail Abuse Prevention System, an organisation that provides anti-spam support...

, were studied and memorized prior to a voyage and were not consulted during a trip, as compared to traditional navigation techniques where consultation of a map is frequent and points and courses are plotted out both before and during navigation. Marshallese navigators used their senses and memory to guide them on voyages by crouching down or lying prone in the canoe to feel how the canoe was being pitched and rolled by underlying swells.

Ocean swells recognized by Marshallese

The Marshallese recognized four main ocean swells: the rilib, kaelib, bungdockerik and bungdockering. Navigators focused on effects of islands in blocking swells and generating counterswells to some degree, but they mainly concentrated on refraction
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...

 of swells as they came in contact with undersea slopes of islands and the bending of swells around islands as they interacted with swells coming from opposite directions. The four types of ocean swells were represented in many stick charts by curved sticks and threads.

Rilib swells

The rilib swell is the strongest of the four ocean swells and was referred to as the "backbone" swell. It is generated by the northeast trade winds and is present during the entire year, even when they do not penetrate as far south as the Marshall Islands. Marshallese considered the rilib swells to come from the east, even though the angle of the winds as well as the impact of the ocean currents varied the swell direction.

Kaelib swells

The kaelib swell is weaker than the rilib and could only be detected by knowledgeable persons, but it is also present year round.

Bungdockerik swells

The bundgdockerik is present year round as well and arises in the southwest. This swell is often as strong as the rilib in the southern islands.

Bungdockeing swells

The bungdockeing swell is the weakest of the four swells, and is mainly felt in the northern islands.

Stick Chart Categories

The stick charts typically fall into three main categories: mattang, meddo (or medo), and rebbelib (or rebbelith).

Mattang charts

The mattang stick chart was an abstract chart used for instruction and for teaching principles of reading how islands disrupt swells.

Meddo charts

The meddo chart showed actual islands and their relative or exact positions. Meddo charts also showed the direction of main deep ocean swells, the way the swells curved around specific islands and intersected with one another, and distance from a canoe at which an island could be detected. The meddo chart portrayed only a section of one of the two main island chains.

Rebbelib charts

Rebbelib charts portrayed the same information as a meddo chart, but the difference lies in inclusiveness of the islands. Rebbelib charts, unlike meddo charts, included all or most of one or both chains of islands.

Passing on stick chart knowledge

Stick charts were not made and used by all Marshall Islanders. Only a select few rulers knew the method of making the maps, and the knowledge was only passed on from father to son. So that others could utilize the expertise of the navigator, fifteen or more canoes sailed together in a squadron
Squadron (naval)
A squadron, or naval squadron, is a unit of 3-4 major warships, transport ships, submarines, or sometimes small craft that may be part of a larger task force or a fleet...

, accompanied by a leader pilot skilled in use of the charts.

It was not until 1862 that this unique piloting system was revealed in a public notice prepared by a resident missionary
Missionary
A missionary is a member of a religious group sent into an area to do evangelism or ministries of service, such as education, literacy, social justice, health care and economic development. The word "mission" originates from 1598 when the Jesuits sent members abroad, derived from the Latin...

. It was not until the 1890s that it was comprehensively described by a naval officer, Captain Winkler of the German Navy
German Navy
The German Navy is the navy of Germany and is part of the unified Bundeswehr .The German Navy traces its roots back to the Imperial Fleet of the revolutionary era of 1848 – 52 and more directly to the Prussian Navy, which later evolved into the Northern German Federal Navy...

. He became so intrigued by the stick charts that he made a major effort to determine navigational principles behind them and convinced the navigators to share how the stick charts were used.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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