Those who have never visited Alaska might assume that the state endures darkness with bitter cold temperatures much of the year. The term "permafrost" might reinforce that notion.Contrary to the misconception of a perpetual winter, the state transforms from a snowy postcard landscape under the dancing Northern Lights into a collection of green mountain ranges under a midnight sun through a "greenup" phase. But below the surface lies a frozen zone, the permafrost, that not only reveals knowledge of life here dating back 40,000 years, but is yielding data about current climate shifts.Only miles north of Fort Wainwright is the world's only permafrost tunnel used for researching how permafrost relates to climate change. The U.S. Army Garrison Alaska, Fort Wainwright Safety Office recently partnered with the U.S. Army Corps of Engineers and Cold Regions Research and Engineering Laboratory to ensure the safety of all tours and digging conducted within the tunnel.While the tunnel itself is the property of USAG Alaska, the Corps of Engineers provides facility services and CRREL, based out of Hanover, New Hampshire, rotates 13 scientists at a time to conduct research throughout Alaska in collaboration with the University of Alaska Fairbanks, NASA and other organizations.With approximately 100 tours given each year to visitors including service members, scientists, community leaders and civilians, ensuring the safety of those working in the tunnel or visiting is vital. Robert Tanner, a safety specialist with USAG Alaska, conducted an annual courtesy safety inspection for the one-of-a-kind facility Sept. 12."We are here to do a courtesy safety inspection; working with the cold regions laboratory out here to look at how they do business, how they do tours, and are they meeting the requirements for a safe work environment," said Tanner.Tanner met with the tunnel's facility operations manager, Gary Larson, prior to one of the day's tours through the tunnel to observe, safety procedures and have an opportunity to ensure all safety requirements are met for a safe, healthy work environment and to those who patron the tunnel."Permafrost is any ground that remains completely frozen (below 32 degrees F or colder) for at least two years straight," Larson explained to a group before entering the tunnel.He said the permafrost tunnel has aided research into links between permafrost and climate changes. Larson told the group about the history of the tunnel and how the Army came to owning the only facility of its kind.Originally a mining claim, digging of the tunnel began in 1963 on the hillside where the research facility is located near Fox, Alaska. The entrance sends visitors to strata dating from around 10,000 years ago. When first opened, researchers were focused on permafrost engineering, which included using the tunnel as a means to protect people and equipment.Since then, research into the tunnel's frozen past has helped scientists better understand how permafrost affects climate change, as well as what animals used to roam the region. Visitors see a mastodon tusk overhead during the tour.Tanner observed as Larson gave the tour group a safety brief ensuring everyone properly wear their hard hats, identified trip hazards throughout the tunnel, noted the minimal risk associated with the dust in the air, addressed the emergency lighting and phones located in the tunnel and what the group would do in the event of an earthquake.Safety inspections of tours and digging inside the tunnel occur twice a year said Tanner.The group donned hard hats and walked into the entrance, and were transported back 10,000 years with Larson pointing out items frozen in time -grass that has maintained enough chlorophyll to cast a shade of green for thousands of years, fossil remains embedded in the walls and ice wedges that run throughout the tunnel.Moving deeper into the tunnel's original portion and on to the newest section, the group was able to observe environments preserved as far back as 40,000 years. Larson explained the significance of each section and how researchers have gained a better understanding of permafrost from the research done inside the tunnel.Tanner said there would be another safety inspection as digging operations start back up this winter."We'll look at those procedures as well as how they're actually conducting them to make sure we meet the requirements for safety," said Tanner.Afterward, Tanner met briefly with Larson to discuss his safety assessment on conducting a tour, identified best practices and his process as a safety specialist moving forward with CRREL and USACE."With everything that we inspect, we'll take this information and we'll provide it to the organization," stated Tanner. "We'll give them the feedback so they can implement that in their procedures and policies and how they do business.