Thursday, November 8, 2012

Isthmuses

I have the pleasure of conversing with V. Garth Norman frequently. He is one of the most astute students of the Book of Mormon in our generation. He, along with many others, believes the narrow neck of land referenced in Alma 63:5Ether 10:20 and possibly Alma 22:32 is the entire Isthmus of Tehuantepec in southern Mexico. I do not believe the text supports that correlation. This article will place Tehuantepec in context among the isthmuses of the world to lay the foundation for relevant Book of Mormon exegesis.

Geographers identify the Isthmus of Tehuantepec as that land in Mexico between the 94th and 96th meridians of west longitude. Its surface area (including water) is 57,629 square kilometers. That is larger than any of the 9 smallest states in the U.S. and nearly the size of West Virginia.
  • 14.40 times larger than Rhode Island, 4,002 square kilometers
  • 8.94 times larger than Delaware, 6,447 square kilometers
  • 4.01 times larger than Connecticut, 14,357 square kilometers
  • 2.55 times larger than New Jersey, 22,588 square kilometers
  • 2.38 times larger than New Hampshire, 24,216 square kilometers
  • 2.31 times larger than Vermont, 24,901 square kilometers
  • 2.11 times larger than Massachusetts, 27,336 square kilometers
  • 2.04 times larger than Hawaii, 28,311 square kilometers
  • 1.79 times larger than Maryland, 32,133 square kilometers
  • 91.83% as large as West Virginia, 62,755 square kilometers
The Isthmus of Tehuantepec is larger than dozens of countries on earth including Croatia (56,594 square kilometers), Denmark (43,094 square kilometers), Taiwan (36,193 squarer kilometers) or Israel (20,770 square kilometers). Placing a north-south transect at the narrowest point, the width of the isthmus between the Gulf of Mexico (Gulf of Campeche) and the Pacific Ocean (Gulf of Tehuantepec) is 216 kilometers. Placing an east-west transect between the 94th and 96th meridians of west longitude, the length of the isthmus is 211 kilometers. The Isthmus of Tehuantepec, as defined by geographers, is shows as a white polygon on the map below. As with all images on this blog, click to enlarge.
Isthmus of Tehuantepec in white, surface area 57,629 square kilometers
Parts of 4 Mexican states are included in the isthmus: Oaxaca, Veracruz, Tabasco and Chiapas. The name comes from the Oaxacan town of Santo Domingo Tehuantepec. The name "Tehuantepec" derives from the Nahuatl "tecuani-tepec" or "jaguar hill". Shortly before the Spanish conquest, the Aztecs conquered Santo Domingo Tehuantepec, but only after a prolonged siege battle. The locals fought ferociously from fortified positions on a prominent hill (summit 120 meters) east of the Tehuantepec River. This Google Earth view shows the hill just above the yellow line representing the Tehuantepec River, on the right hand side of the image with the modern town built up around it.
Modern town of Santo Domingo Tehuantepec showing jaguar hill
Because the natives fought like jaguars on their hill, the Aztecs named the place tecuani-tepec.

4 major river systems drained the isthmus during Book of Mormon times: the Papaloapan, Coatzacoalcos, Tehuantepec and Mezcalapa-Grijalva (today the Tonala). On the  map below, the Mezcalapa-Grijalva system (as it flowed in Book of Mormon times - see the article "Wandering River" in this blog) is in blue, the Usumacinta is in red, other rivers are in yellow, the continental divide is in white, and the trans-isthmian railroad is shown in magenta. It requires 302 kilometers of track for the railway to connect Salina Cruz, Oaxaca with Coatzacoalcos, Veracruz. The railroad crosses the continental divide at Chivela Pass, altitude 224 meters.
Isthmian rivers, continental divide and railroad
Chivela Pass funnels prevailing winds, known as Tehuanos, from south to north. Occasionally, contrary winds blow through the pass in the opposite direction, from north to south, with such force that they have been known to sandblast paint from ships in the Gulf of Tehuantepec. The largest wind power project in Latin America is currently under development on the Oaxacan side of the isthmus. Elevations within the isthmus range from 2,500 meters to sea level. Five different climatic zones are present in this area. The following map shows the world standard Koppen climate classification system for Mexico.
Koppen climate map of Mexico showing five zones within the isthmus
In general, the southern side of the isthmus is much drier than the northern side. This is graphically shown in a NASA true color satellite image taken in April at the height of the dry season.
NASA Blue Marble image of the isthmian region in April
Satellite images of the earth's lights at night provide a good visual representation of relative population density. Notice that in the Tehuantepec region, both coasts are heavily populated while the interior Selva Zoque remains largely in its natural state.
NASA image of the earth's lights at night
This same pattern held true anciently. Plotting archaeological sites known to science from the EAAMS database, we find settlement activity on both coasts with a large blank spot in the middle.
Known archaeological sites
The point is that the Isthmus of Tehuantepec is a very large place with a great deal of physiographic and cultural diversity. How large is it? It is the widest isthmus on the planet (Panama is the longest). Geographers consider anything wider than Tehuantepec part of a continental land mass rather than an isthmus. Some geographers even consider Tehuantepec too wide to be classified as an isthmus. Here is a comprehensive, although not exhaustive, list of generally accepted isthmuses (aka isthmi) organized in ascending order by width at the narrowest point:
Isthmuses of the World
Isthmus Between and Width (km) Notes
Bruny Island, Tasmania North Bruny South Bruny 0.04
Olympia, Washington West Olympia East Olympia 0.04
Nahant, Massachusetts Nahant Masachusetts 0.06
Quetrihue, Argentina Quetrihue Peninsula Neuquen, Argentina 0.09
Mavis Grind, Shetland Islands North Mavine Peninsula Shetland 0.11
La Coupee, Sark, Channel Islands Little Sark Sark 0.12
Eaglehawk Neck, Tasmania Tasman Peninsula Tasmania 0.14
Portland Beach, U.K. Portland Bill Dorset, England 0.16
Bardsey Island, U.K. North Bardsey South Bardsey 0.19
Derbyhaven, U.K. Langness Peninsula Isle of Man 0.20
Coronado, California Coronado Island California 0.25
Saint Pierre and Miquelon, Newfoundland Island of Miquelon Langlade Island 0.25
Sutton, Dublin, Ireland Howth Ireland 0.37
Cape Clear Island, Ireland Gathabawn Cape Clear 0.43
Kushimoto, Japan Cape Shiono-Misaki Honshu Island 0.47
Catalina Island, California Western Catalina Eastern Catalina  0.61
Munoz Gamero Peninsula, Chile Munoz Gamero Chile 0.80
Madison, Wisconsin Lake Mendota Lake Monona 0.93
Bolbs, Spain Gibraltar Spain 1.08
Potidea, Greece Kassandra Peninsula Greece 1.08
East Falkland Island Northern East Falkland Southern East Falkland 1.24
Sechelt, British Columbia Sechelt Peninsula Canada 1.25
Llondudno, Wales Great Orme Wales 1.29
Rongotai, New Zealand Miramar Peninsula North Island, N.Z. 1.31
Similk Beach, Washington Fidalgo Island Washington 1.75
Tarbert, Scotland Kintyre Peninsula Scotland 2.17
2.96 median
Auckland, New Zealand Northern Peninsula North Island, N.Z. 3.75
Seattle, Washington Puget Sound Lake Washington 4.00
Medanos, Venezuela Medanos Peninsula Venezuela 4.05
Summerside, Prince Edward Island Western P.E.I. Prince Edward Island 4.12
Carlos Ameghino, Argentina Valdes Peninsula Chubut, Argentina 5.07
Avalon, Newfoundland Avalon Peninsula Newfoundland 5.75
Corinth, Greece Peloponnese Peninsula Greece 5.80 etymological origin
Perekop, Crimea Crimea Ukraine 9.46
Westfjords, Iceland Westfjords Peninsula Iceland 9.47
Rhins of Galloway, Scotland Galloway Peninsula Scotland 9.60
Maui, Hawaii West Maui Maui 11.00
Quezon, Philippines Bicol Peninsula Luzon 12.00
Punta Arenas, Chile Brunswick Peninsula Chile 15.00
Rivas, Nicaragua Lake Nicaragua Pacific Ocean 18.00
20.20 mean
Ofqui, Chile Taitao Peninsula Chile 21.00
Chignecto, Nova Scotia Nova Scotia Canada 24.00
Adam's Bridge (former isthmus), India India Sri Lanka 29.00
Catanzaro, Italy Calabria Peninsula Italy 30.00
Kra Isthmus, Thailand Malay Peninsula Asia 43.00
Karelian Isthmus, Russia Gulf of Finland Lake Ladoga 46.00
Forth-Clyde, Scotland Scottish Highlands Central Lowlands 50.00
Panama Central America South America 57.00
Suez, Egypt Sinai Peninsula Egypt 122.00
Olonets, Russia Lake Onega Lake Ladoga 125.00
Onega, Russia Lake Onega White Sea 154.00
Tehuantepec, Mexico North America Central America 216.00
20.20 mean
2.96 median
If you want to play around with the data, you can download the Excel spreadsheet here by clicking on file, then download.

The word "isthmus" derives from the Greek "isthmos" meaning "neck". The use of the term in geography originated with the Isthmus of Corinth which is 5.80 kilometers wide at its narrowest point.
Isthmus of Corinth (Korinthos) in Greece
The Isthmus of Corinth joins the Peloponnese Peninsula to the Greek mainland. It is about 7.45 kilometers long and has a surface area of approximately 56 square kilometers. The modern Greek village of Isthmia is at the narrowest point of the isthmus.

The Isthmus of Paracas in Peru, 4.61 kilometers wide, is typical. The atypical Isthmus of Tehuantepec is 37 times wider (216 kilometers/5.80 kilometers) than the Isthmus of Corinth which defines the genre.