Tuesday, October 6, 2015

Carlsbad Caverns National Park

Carlsbad Caverns National Park in New Mexico began as Carlsbad Caverns National Monument in 1923 and was elevated to national park status in 1930. In 1978, Carlsbad Caverns Wilderness was established to protect the area above the caves. Hidden beneath the surface are more than 119 known caves - all formed when sulfuric acid dissolved the surrounding limestone leaving behind caverns of all sizes.

The Natural Entrance was created by erosion above ground within the last million years, and exposure to the surface has allowed for the influx of air into the cavern. Self-guided and ranger-led tours of Carlsbad Cavern are available daily. A general admission ticket must be purchased for access to two self-guided trails. Ranger guided tours reservations may be made in advance or purchased at the park. Carlsbad Caverns sees an average of 407,211 visitors every year. The highest attendance seen in a year was 876,500 visitors in 1976. As of 2011, a total 41,654,278 visitors had entered the park

The entrance trail is a steep 1¼-mile descent equivalent to about 79 stories, from the cave entrance to the Big Room. This walk is recommended only for those in good physical condition. Big Room Trail may be also accessed from the elevator. The trails are steep, so wear sturdy, closed-toe shoes.

Carlsbad Cavern begins in a large cave chamber called the Big Room, a natural chamber that is almost 4,000 feet long, 625 feet wide, and 255 feet high at its highest. It is the fifth largest chamber in North America and the twenty-eighth largest in the world. The Big Room is easily the most visited at Carlsbad Caverns. Heavily decorated with cave formations, wide-open spaces, and relatively flat, it is a must-see. The 1.25 mile trail winds around showing off areas like the Hall of Giants, Bottomless Pit, and Crystal Spring Dome. A short-cut is available that cuts the length and duration of the Big Room Trail in half. Photos can never fully capture the grandeur of the Big Room -- it's a place you need to see to believe! Allow one to two hours to walk the entire Big Room Trail.

Carlsbad Cavern is 56°F year round, so a light jacket or long-sleeved shirt is recommended. The trails and cave features are electrically lit, but bring a flashlight if you like. The cave is very humid, so bring your inhaler if you use one.

Carlsbad Cavern is one of over 300 limestone caves in a fossil reef laid down by an inland sea 250 to 280 million years ago. Twelve to fourteen thousand years ago, American Indians lived in the Guadalupe Mountains and some of their cooking ring sites and pictographs have been found within the present day boundaries of the park. In 2003, a park employee found a piece of a stone scraper within view of Carlsbad Cavern's entrance that goes back to Ice Age Indian hunters. In 2004, archeologists found fragments of two spear points of the Midland-style Paleo Indian projectile points of some 10,000 years ago.

By the 1500s, Spanish explorers were passing through present-day west Texas and southeastern New Mexico. Spain claimed the southwest until 1821 when Mexico revolted against her and claimed independence. Mexico, fighting the westward expansion of the United States in the late 1840s, lost the southwest to the US. In 1850, New Mexico Territory was created and for the next 30 years the cultural conflict between American Indians and the US government continued. Eddy, New Mexico, the future Carlsbad, was established in 1888 and New Mexico became a state in 1912.

Native Americans who lived in the area for centuries and early local residents knew about the cave. We credit Jim White for being the first "explorer" of the cave in 1898. While a young boy, he explored the cavern with his homemade wire ladder. When he grew older and told of his adventures, there was considerable doubt as to whether the caves actually existed. He named many of the rooms, including the Big Room, New Mexico Room, Kings Palace, Queens Chamber, Papoose Room, and Green Lake Room. He also named many of the cave's more prominent formations, such as the Totem Pole, Witch's Finger, Giant Dome, Bottomless Pit, Fairyland, Iceberg Rock, Temple of the Sun, and Rock of Ages. 

The 120 caves of Carlsbad Caverns National Park were not carved out by running water and streams like many limestone caves in the world, but rather was dissolved along cracks and faults in the limestone rock by sulfuric acid.

The limestone was laid down about 250 million years ago as part of a reef complex along the edge of an inland sea. Seventeen to twenty million years ago, the ancient reef rocks that had been buried under thousands of feet of younger rocks began to lift upwards. Tectonic forces pushed the buried rock layers up and erosion wore away softer minerals to expose the ancient reef as the Guadalupe Mountains.

Deep in the basin, a brine originating from oil and gas deposits and rich in hydrogen sulfide was forced into the limestone at the edge of the basin. When this brine encountered oxygen-rich rainwater moving down through the rock, it created sulfuric acid. This acid dissolved the limestone creating cave passages. As the Guadalupe Mountains continued to lift up, the water drained out of the cave allowing fresh water to percolate through and leave minerals on the ceiling, walls, and floors that we know as cave decorations.

Above the ground in the Chihuahuan Desert, high ancient sea ledges, deep rocky canyons, flowering cactus, and desert wildlife all thrive. Approximately two-thirds of the park has been set aside as a designated wilderness area to ensure no future changes will be made to the desert and mountain habitats, because what is on top of the caves is directly responsible for what happens to the caves.

These caves were dissolved by very aggressive sulfuric acid. Once rainwater trickles down through the soil and picks up carbon dioxide gas, it creates carbonic acid, the acid dissolves the limestone, and then re-deposits it in the cave as calcite decorations.

Scientists call the cave formations "speleothems." The carrot-like ones clinging "tight" to the ceiling are stalactites. Stalagmites form on the cave floor and "grow" up toward the ceiling. Different formations of speleothems include columns, "Soda straws," draperies, Helictites, and "Cave popcorn."  Changes in the ambient air temperature and rainfall affect the rate of growth of speleothems, as higher temperatures increase carbon dioxide production rates within the overlying soil. The varied colors of speleothems is determined by the trace constituents in the minerals of the formation.

One of the special events hosted by the park is the viewing of a bat flight. Nightly programs are given in the early evening at the amphitheater near the main entrance prior to the start of the bat flight, which varies with the sunset time. Flight programs are scheduled from Memorial Day weekend through the middle of October. Optimal viewing normally occurs in July and August with the arrival of the bat pups in addition to the normal migratory bats. Morning programs are also hosted pre-dawn to witness the return of bats into the cave.  Nearly 400,000 Brazilian Free-tailed bats call Carlsbad Cavern home in the summer, and all they want to do each night is eat bugs, several tons of them!

Until 1932, visitors to the cavern had to walk this switch back ramp-sidewalk that took them 750 feet below the surface. The walk back up was tiring for a lot of visitors. In 1932 the National Park opened up a large visitor center building that contained two elevators that would take visitors to the caverns below. The new center included a cafeteria, waiting room, museum and first aid area. Located in the Big Room at the head of the Left Hand Tunnel, it contains a cafeteria that was built in the 1950s and is where the elevators from the visitor center exit into the cave.

Lechuguilla Cave was known until 1986 as a small, fairly insignificant historic site in the park’s backcountry. Small amounts of bat guano were mined from its entrance passages for a year under a mining claim filed in 1914. The historic cave contained a 90-foot entrance pit which led to 400 feet of dry, dead-end passages. The cave was visited infrequently after mining activities ceased.

In the 1950s, cavers heard wind roaring up from the rubble-choked floor of the cave. Although there was no obvious route, people concluded that cave passages lay below the rubble. A group of Colorado cavers gained permission from the National Park Service and began digging in 1984. The breakthrough led into large walking passages on May 26, 1986. What followed has become some of the world’s most exciting cave exploration in one of the finest known caves on the planet.

Since then, explorers have mapped 138 miles of passages and have pushed the depth of the cave to 1,604 feet, ranking Lechuguilla as the 5th longest cave in the world (3rd longest in the United States) and the deepest limestone cave in the country. Cavers, drawn by unexplored passages and never-before-seen beauty, come from around the world to explore, map, and study this beautiful underground wilderness. Access to the cave is limited to approved scientific researchers, survey and exploration teams, and NPS management-related trips.

Below is one of the new areas called Chandelier Ballroom.

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