The tower rising above the palace in Palenque is unique. This structure is built as a functional edifice and was erected of cast-in-place concrete beams at various levels supported by a cast-in-place concrete wall. The interior stairway leads to the top of the tower. The tower is assumed to have been an observatory for viewing the stars. However, the hilly terrain and the height of the towering rainforest surrounding the tower blocks the nighttime sky from a view from the top platform, casting doubt on its effective use as an observatory.
The two cast-in-place concrete towers supporting the long-span suspension bridge over the Usumacinta River at Yaxchilan (Figure C-22) were 25 meters in height. The tower structure was topped with a Maya vault structure. The vault was part of the bridge support system and included connections for the suspension cables.
The Rio Bec style of architecture featured tall towers rising out of an elongated base structure. The number of towers at specific sites varied in height and number. Xpuhil, with three towers of great height, has the most impressive structural and architectural design of the Rio Bec style. Becán has two towers, and Chicanná and Rio Bec have single towers. The towers constructed in the Rio Bec style are unique in the Maya world. Their purpose is unclear to archaeologists. The towers are built with tapering cross-sections as they rise from the base. They were tapered upward to create a vertical perspective and to appear taller. The exterior stairways were nonfunctional and were carved from the facing stone. The temples and their accoutrement, including the doors, were carved from stone.
The facades of many Maya towers were carved with magnificent art and were painted with colors that reflected the regional style of art and architecture. The structural systems employed for the tower construction consisted of an outer shell of cut limestone block and an interior structure of mass cast-in-place concrete. The interior of towers usually had stairways in order to reach upper levels.
Palaces
The power elite lived in large palatial residences that were adorned in brilliantly colored sculpture and paintings in the regional style. Palaces were large buildings with numerous rooms. They were constructed as single story and multistory structures. Palaces varied in size and height of living levels, as well as in size, from 200 rooms at Cancuén, Guatemala, to five stories in height at Edzná, Mexico.
The vaulted exterior chambers of palaces were aligned with the facades to maximize wall openings for natural ventilation. The Maya vault structural system was the major element for the construction of palaces. In multistory palaces, the second and third levels were set back to align their outer walls with the inner wall of the lower story (Figure 7-7 and Figure C-13). In some cities, palaces were designed and constructed with ventilation, running water for plumbing and fountains, and interior stairs.
8
Survival in the Seasonal Desert
Northern European cultural lore endorses the notion that technical innovation is stimulated by the need to survive and prosper in a frigid climate. They argue that organized civilization is not possible without the technical innovations required to overcome the negative effects of the natural environment. Their concepts hold that technological development is unnecessary in tropical environments where resources and manpower are not required for the collection and storage of food and fuel for warmth during cold weather. They endorse the notion that the enchanted tropical climate creates a blissful lifestyle where life is easy and scantily clad natives prance about as they pick ripe fruit off the trees.
The domain of the Maya is sited completely in the tropics in a location more than 750 miles (1,800 km) south of the Tropic of Cancer. Maya engineers proved that their feats of tropical technology were, in fact, more sophisticated than the technology of their Northern European counterparts at similar stages of cultural development. The tranquil climate of the Yucatán Peninsula released the Maya from the necessity of cutting fire-wood for warmth, manufacturing warm clothing for the cold, storing food for winter, and constructing weather-tight residences. However, they faced a fickle environment that demanded engineering measures beyond the ken of Northern European technology. The natural environment deprived them of a dependable supply of water from rainfall or the aquifer. The verdant and torrid environment of the Yucatán manifested serious natural liabilities that challenged the survival of the Maya; they faced the constant specter of thirst. Maya water-management technology solved the dilemma and provided a dependable water supply that enabled the civilization to survive and prosper.
The skill and technology of the ancient Maya enabled them to dominate their environment for more than 3,000 years. They developed methodologies to overcome the foibles of the environment and enabled the survival of the world’s largest cities—cities that supported some of the densest populations in history. (The population density at Tikal, Guatemala was on a par with the density of modern Los Angeles.) Maya engineers developed efficient projects that sustained the civilization by providing potable water systems, irrigation for agriculture, aquaculture techniques, and water storage systems.
The search for Maya water-management technology, once the exclusive realm of archaeology, has been joined by archaeo-engineers, NASA satellite mapping scientists, and other crossover researchers. The success of the new disciplines of archaeo-engineers has advanced the known body of knowledge of the lost technology of Maya water-management engineering. These experts are using digital tools, including remote sensing and computer simulations, to raise the veil of secrecy hiding the lost treasures of Maya water-management engineering.
Maya engineers were faced with a double whammy that had to be overcome: six months of heavy precipitation, from roughly May to October, followed by a dry season between November and April. In addition, voluminous amounts of storm water fell on the porous limestone landscape, which drew in the water directly down into the deep aquifer. The end result was a seasonal desert and a lack of natural surface water that would, if it existed, have provided year-round water supplies for the populace. These natural characteristics of the environment would have daunted the most ambitious of Northern European technologists. The unique character of the Maya environment was significant to astute observers of the area. The famed Diego de Landa, bishop of the Yucatán, wrote in his 1566 book, Relacion de las cosas de Yucatán, of the character of the land and water supply in the Yucatán, “In this respect, nature has acted differently in this country from the rest of the world, where the rivers and springs flow above the ground whereas here all run in the secret channels underground.”
The solution involved the capture of the massive volume of storm water that fell during the rainy season, then the collection and storage of that water to provide an ample supply for the needs of the cities and irrigation for agriculture. Maya civil engineers faced Mother Nature’s challenge and applied their ingenuity to develop different solutions for locations that had different water source issues. These solutions involved optimization of aquifer-fed well water supplies, collection of water into underground storage reservoirs and surface water reservoirs, and an aqueduct water-supply systems.
The Seasonal Desert
The Yucatán Peninsula encompasses a varied landscape and a wide range of climatic conditions. It extends from the mountains of the Sierra Madre, to the dense canopied rainforests of the interior, to the extensive wetlands, mangroves, and coral lagoons that constitute the Caribbean coastal area. The Yucatán lies within the Atlantic hurricane belt, directly in the path of powerful hurricanes and tropical storms that traverse the Atlantic from the coast of Africa and travel westward into the Caribbean. The damaging winds and torrential rains from tropical storms and hurricanes were a threat to life, and a challenge to the hydraulic and structural engineering capabilities of Maya technology.
The world of the Maya lies well below the Tropic of Cancer. The Yucatán is cloaked in a hot, humid, tropical climate with some of the heaviest annual rainfall in the tropics. The rainfall ranges from 40 inches (1,000 mm) in the Northeast to 200 inches (5,000 mm) on the Eas
t Coast. As much as 90 percent of storm water falls during the rainy season. The average percentage of days per month with rainfall varies from 25 percent during the rainy season to only 7 percent of the days in the dry season. The average temperature in the Yucatán is 92 degrees F (32.3 degrees C). The highest average temperatures occur in July and August, when the highest daily temperature may reach 100 degrees F (38 degrees C), and low temperatures rarely extend below 65 degrees F (18 degrees C).
The common image of the Yucatán conjures up lost cities slumbering under a canopy of tangled rainforest vegetation. The placid images of this lush and verdant environment are misleading. The heavy tropical vegetation depends on the torrential precipitation during the rainy season. During the dry season, the rainforest depends on moisture from its tap roots, which extend deep down into the aquifer. This phenomenon of alternating periods of heavy rain and drought-like conditions turns the Yucatán Peninsula into a seasonal desert. The lack of surface water leaves the area totally without a source of water during the dry season. A seasoned explorer knows that one can easily die of thirst during the dry season while wandering in the lush, humid rainforest.
The cyclic wet/dry contrast of the seasons is the result of a meteorological phenomenon stemming from the seasonal migration of precipitation associated with the inter-tropical convergence zone. This inter-tropical convergence zone migrates to the South during the winters, leaving the Yucatán in drought-like conditions for six months. This atmospheric condition, known as the meteorological equator, results in a northern shift of the zone during the summer, and with this shift, heavy rains come to the Yucatán.
Unlike other great civilizations that selected riverine sites for their cities, the Maya did not have the luxury of establishing major cities along natural water sources. The exceptions were a handful of cities that were fortunate enough to found their cities on the few natural water sources in the Yucatán. The majority of important Maya city-states developed in locations without permanent water sources. Great cities such as Tikal, Caracol, and Calakmul selected locations with natural terrain that offered advantageous defensive characteristics for their city and features that enhanced the potential to collect, store, transport, and distribute life-giving water for the population of the cities and for agricultural irrigation.
The heuristic technology of the Maya civilization triumphed over the fickleness of nature. Maya engineers optimized their technology and overcame the lack of water that characterized the seasonal desert. The innovative solutions included the diverse technologies of civil, hydraulic, and structural engineering. The solutions assumed many roles, including shaping the slopes of the roofs of the buildings, landscapes, and hardscapes to structured storage systems and enhancement of natural sources of water.
Geological Features of the Yucatán
Hundreds of millions of years in the past, an ancient ocean deposited the skeletal remains of marine micro-organisms and coral that became the sedimentary rock that forms the karstic limestone foundation of the Yucatán. Karstic limestone has a characteristic physical feature that includes small-scale fissures and voids. Despite its extraordinary biological richness and some of the heaviest rainfalls in the tropics, with very few exceptions, there are no lakes and virtually no surface streams on the Yucatán Peninsula. The heavy flow of storm water rapidly percolates downward through the shallow soil layer and into the permeable limestone, and is deposited into a network of caves, subterranean rivers, and channels that form the aquifer. The complex underground system of conduits swiftly transports water through the aquifer away from the central area of the peninsula and into the Caribbean Sea. The aquifer manifests itself as freshwater surface springs along the coast of the Caribbean Sea.
An extraterrestrial visited the Yucatán 65,000,000 years ago and changed the course of earth’s history. It is unknown if the extraterrestrial was a meteor, asteroid, or a comet. Its impact with the northern coast of the Yucatán generated a cataclysm that circled the planet: a 2-kilometer-high tsunami sped across the oceans and inundated shorelines, fire storms raged across the earth, and dust blotted out the sun, casting the planet into darkness. A sudden cooling of the atmosphere and an increase in sulfur content snuffed out life on the earth’s surface.
The impact triggered the K-T (Cretaceous/Tertiary) extinction of the majority of the planet’s animal life, most notably the dinosaur. Burrowing mammals, which were fairly small, furry creatures, survived and evolved into biological niches formerly occupied by reptiles and replaced the dinosaurs as the dominant land animal. These little guys became our ancestors.
The linking of the extinction of the dinosaurs with a catastrophic extraterrestrial impact gained international acceptance with the 1980 Nobel Prize–winning theory by Louis and Walter Alvarez. The giant Chicxulub Crater in the northern Yucatán is considered the best candidate for ground zero for the catastrophe and causing the K-T layer (Figure 8-1).
Geologists have concluded that a 10-kilometer-wide bolide, or exploding meteor, collided with the earth on the northern edge of the Yucatán near the present-day town of Chicxulub. This event closed the Cretaceous period. The famous ring of cenotes outlines the shock waves of the impact, and it was discovered that the K-T boundary contains higher concentrations of iridium than normally occur in the earth’s crust. The earth was covered with this “ejecta blanket” from the Chicxulub blast.
The outer perimeter of the 183.3-kilometer-wide crater was fractured by the blast of the impact (Figure 8-1). As time passed, the limestone covering the fractured limestone dissolved, reducing the surface thickness and the affected surface area collapsed. The surface openings in these natural wells exposed the waters of the deep Yucatán aquifer and created the complex of natural wells called cenotes. The pattern of natural wells formed the famous ring of cenotes, which became the sources of life-giving water for the Maya in the Northern Yucatán. It is ironic that the extraterrestrial that destroyed so much of life on earth would re-emerge as part of the history of Mesoamerica. The 65,000,000-year-old alien intruder that formed the cenotes would partner with Maya technology to provide water for the Maya civilization.
Figure 8-1: NASA image of Chicxulub Crater indicating cenotes in white. Courtesy of NASA.
Maya Technology to the Rescue
It was a rarity for Maya cities to be located on a permanent source of running water. However, ancient Maya cities located near the ring of cenotes in the northern Yucatán had a choice of hundreds of permanent, natural wells when siting their cities. The city of Cobá was founded on a series of lakes fed by a shallow aquifer that assured the city a dependable supply of water. The ancient cities of Yaxchilan, Copán, and Piedras Negras were sited on rivers that supplied water and provided transportation resources. The city of Palenque was fortunate to be located on a site with a surfeit of free-flowing water from natural springs. These cities were, however, the exception to the rule and had other water-management issues, but a lack of a reliable water supply was not one of them. The vast majority of Maya cities required engineering solutions to assure a dependable source of fresh water.
As the population of the Maya civilization grew, its technological capabilities evolved into a positive force that overcame the daunting natural obstacles that impeded the survival, health, prosperity, and growth of Maya city-states. Early Maya technicians recognized the threat of the hostile environmental and the fragility of the water supply. Water-management technology, driven by the demands of the expanding population, overcame the obstacles of the environment. Maya technicians were charged with developing means to deliver and maintain a constant supply of clean water. However, when engineers pondered the development of water resource systems, they had two strikes against them. They had to face the dual challenge of a capricious rainfall creating a seasonal desert in the Maya domain, exacerbated by the porous karstic landscape that intercepted their collection efforts by drawing down storm water directly into the aquifer. Maya engineers respected the powerful impact of their fickle envir
onment and the sponge-like characteristics of their geology. They understood the foibles of the environment, and configured their cityscapes and civil works to optimize the collection, storage, and distribution of storm water.
Maya engineers delivered innovative water-management systems integrated with advanced agriculture systems to develop increased crop production. Advances in agriculture yield were developed through a variety of intensive technologies including raised fields, terraces, and irrigation systems. The pressure on developing sustainable sources of water peaked during the late Classic Period, when the Maya population reached its maximum. In AD 750, the population of the Maya world may have peaked at 15,000,000 people. The majority of the population resided in urban centers. Dr. Tom Sever, NASA archaeologist, has opined that the Maya population was one of the densest populations in human history. Using satellite data and climate models, Dr. Sever determined that population levels reached an all-time high after AD 800. Population density ranged from 500 to 700 people per square mile in the hinterlands and up to 1,800 to 2,600 persons per square mile in the urban center of city states. By comparison, modern-day Los Angeles County averaged 2,345 people per square mile.
Maya technology developed innovative water-management techniques and structures to satisfy the year-round demand for fresh water, which included systems for collection, storage, and distribution. The solutions for water acquisition and distribution assumed multiple technical configurations based on the variation in the dispositions of water sources. Water sources included deep natural wells called cenotes, underground storage structures called chultunes, large scale open reservoirs, and underground aqueduct structures.
The Lost Secrets of Maya Technology Page 18
