Tennessee offers a range of exhilarating outdoor experiences, from hiking picturesque valleys to climbing craggy gorges. These activities are not only enjoyable but also provide insights into geological formations and processes.
As a geologist, I have had the opportunity to explore some of the world’s most intense terrains, including the Andes, Middle Eastern deserts, the Balkans, and the Appalachians. Each region presents unique geological features that enrich our understanding of Earth’s history and processes.
29, 2026. In 2018, a flash flood in Israel’s Tzafit Canyon – an environment similar to the part of the Grand Canyon where the 2026 flood occurred – claimed the lives of 10 recent high school graduates who were hiking in the canyon. At Grand Canyon National Park in Arizona, at least two hikers died and a third was missing after powerful monsoon storms sent a deluge into one of the narrowest parts of the canyon on Aug. Two of the survivors who were rescued described seeing the water quickly rise over the trail as they clung to a ledge, fearing they might never see their families again. In canyons and arroyos – steep gullies common to the Southwest – flash flooding can occur even when the heavy rainfall happens great distances away. A person can be hiking under clear skies in the canyon and not be aware that heavy rain falling upstream or even outside of the canyon means a disaster is unfolding. The steep gradients and narrow passageways that define these landscapes channel the water, sending vast amounts of it rushing downstream. Under these conditions, water can rise quickly in the narrow space of a canyon. The Grand Canyon flood involved heavy downpours in the heart of monsoon season. The intensity of the rainfall matters in a canyon. Even in arid regions, which generally get low amounts of rain annually, heavy rainfall within a short period of time can create devastating floods.
Be aware that the timing of floods can vary widely – scientists analyzed 74,814 flash flood events in the U.S. and found the average duration was around 3½ hours, but some persisted for more than 48 hours. Carefully study your environment before going in, so you know the risks and the escape routes that will let you get to safety in the event of a flash flood. Always be aware of the weather – not just above you but upstream. Clear skies can be deceptive. An added challenge is that cellular service is often shaky in deep canyons and remote areas. Check the weather forecast before you go down a canyon, not just for the specific location, but also for the surrounding area. The National Weather Service provides warnings of flash floods and other extreme weather events. If heavy rain starts, use extra caution and seek higher ground. A flood can start quickly and strand people for long periods of time. Muddy water or debris in a normally clear stream are two signs of flooding developing. Rising water or the distant sound of rushing water is another clear warning to get to safety fast.
