International Year of Caves and Karst 2021—NPS Celebrates!

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caver in wet area of cave with stalactites and stalagmites
A caver explores stalactites and stalagmites in a wet area of Jewell Cave. In the U.S., karst landscapes hold 40% of our groundwater. Jewel Cave National Monument, South Dakota. NPS photo.


The National Park Servide is joining in the celebration of The International Year of Caves and Karst (IYCK) to help raise the level of understanding and respect for caves and karst as globally important physical, ecological, and cultural systems.The IYCK will be the largest ever event showcasing caves and karst landscapes across the world.

Caves are natural laboratories for preserving fossils, minerals, and records of past climates. Caves also provide habitats for unique and rare animals. Karst is a type of landscape that forms when rocks are dissolved by weak acids. Features that are often characteristic of karst terrains include caves, sinking or disappearing streams, sinkholes, and springs. The National Park Service manages approximately 5,000 caves, including four of the top 10 longest caves in the world. In the United States, 40% of fresh groundwater that we drink comes from karst aquifers.

The National Park Service and the National Natural Landmarks Program invite you to join in the celebration. Caves and karst areas are part of America’s Geoheritage because of their significant values, uniqueness, and diversity of natural features. We hope you can join us in the celebration and Discover What’s Under Your National Park!

Featured Articles

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    IYCK 2021 Regional Art Contest

    15 PHOTOS

    Thank you to everyone who entered the IYCK 2021 Regional Art contests. Thanks also to the cave sites that sponsored a contest in their area. This album contains first place artwork from regional art contests that were forwarded to compete in the National Contest. Judging for the National contest will take place in October, 2021.

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    Monthly Themes and Highlights

    September—Lava Tubes and Other Dark Places

    Theme: Caves can form in a variety of rock types and locations

    Introduction: Lava tubes or caves are hollow spaces beneath the surface of a solidified lava flow. When molten, fluid lava flows out of a volcano, it works its way downhill. In contact with air, the surface of this lava stream cools and hardens into a crust. The lava inside remains molten, however, and continues to flow downhill. When the molten lava eventually drains out of the interior of the hard-crusted passage, a lava tube or cave remains.

    Topics: Formation, features, examples

    Hashtags: #CaveLavaTubes

    Featured Links:

    Related Links

    Themes—Explore Further

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    Stay Connected

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    Visit "Explore Nature" on social media.


    Share Your #IYCK2021

    Join the vibrant virtual community of stewards, educators, and cavers in celebrating #IYCK2021. Spread the word on Facebook, Twitter, and Instagram, and share opportunities to learn and interact.

    Connect with Cave and Karst Sites

    Solution Caves

    Lava Tubes

    Sea or Littoral Caves
    Talus Caves
    Karst Landscapes
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    Featured Opportunities

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    Three Sources of Light Podcast—Carlsbad Caverns
    Join park rangers for in-depth conversations that illuminate the diverse natural and cultural resources of Carlsbad Caverns National Park. The podcast is produced by the Interpretation Division at Carlsbad Caverns National Park. New episodes will be posted periodically throughout 2021.

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    Cave and Karst Art Contest—"Discover what's under your National Park!"
    The National Park Service and International Year of Caves and Karst (IYCK) partners are sponsoring an art contest to celebrate the International Year of Caves and Karst in 2021. There will be two chances to win—national parks will host their own regional contest and the winners will advance to the national level. Artwork will be accepted starting February 1st and ending June 12th, 2021.

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    Celebrate Cave Week! June 6th – June 12th, 2021
    Dozens of parks across the country participate in Cave Week by offering special tours, events, and web-based activities. Celebrate and share #CaveWeek.

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    Become a Junior Cave Scientist
    Explore a fascinating and fragile underground world. Learn about caves and karst landscapes. Complete a few fun activities.

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    Virtual Tour of Lehman Caves—Great Basin National Park, Nevada
    Take a three part video tour—created from 3D imagery!—through the amazing subterranean world of Lehman Caves.

    Explore Further


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    Last updated: September 14, 2021


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