*** To qualify a find for this cache, we ask that the seeker state the time of day and how many of the steps down into the pool (not including the platform) are covered with water. Also, please estimate the difference in elevation between the Blue Hole and another nearby water feature (to do this, find the elevation at the nearest open water and the elevation at the Blue Hole and compare the two - there are a few very nice lakes in the Santa Rosa area and this is a great excuse to visit & enjoy them). Send your answers through the Message Center or by email through our profile -- do not post your answers in your log or it will be deleted. A photo of yourself at the pool would be appreciated too, but is not mandatory.***
** UPDATE 6/14/2021: There is now a $10 per vehicle parking fee. Thanks to GeoquackerO> for bringing this to our attention. Way back when we placed this EC, it was just a big dirt lot... now it is a tourist attraction! **
The Blue Hole in Santa Rosa, New Mexico is a natural, bell-shaped artesian spring. It is 81 feet deep and has a constant water temperature of 64 degrees. The pool is amazingly clear and a bright turquoise blue. Artesian springs are formed from aquifers, which are underground water sources within layers of water-bearing porous stone, earth, or gravel. In the case of the Blue Hole, the material is sandstone. Water, usually from rainfall, builds up over time, permeating the sandstone. As more and more water saturates the sandstone, the pressure increases and eventually the water must move. Gravity and rock density determine the path, and the water follows the path of least resistance. When water within an aquifer is confined at sufficient pressure to cause the water surface to rise above the surface of the ground, such formations are said to be functioning under artesian conditions. They can come through faults and softer layers of sediment, or flow through caverns. So to simplify - an artesian is a confined aquifer that has found a way for the groundwater to flow upwards due to pressure.
The Blue Hole was produced from a cave system near the well's bottom (the access to this cave system has been permanently sealed with a steel grate for safety). Water flows into the hole at 3,000 gallons per minute, recycling the water every six hours. The Blue Hole is a very popular spot for SCUBA divers and can be an extremely busy place to visit. The spring is 4,600' above sea level making the bottom equivalent of over 100' of depth in the ocean. Considering this, diving to the bottom would be considered an "altitude" dive and specialty SCUBA courses in Altitude Diving are often taught here. Since driving to a higher elevation after a dive would basically be the same as flying after diving, divers have to observe special rules after conducting an altitude dive. Divers heading back to Albuquerque after diving the Blue Hole have to off-gas several hours because the highway crosses a mountain ridge of more than 7,000 feet.