The U.S. Army Corps of Engineers has received a mission assignment from FEMA in advance of the winter storm which is expected to affect multiple regions. We are pre-positioning assets, including generators, capable of supporting temporary emergency power needs. Teams from Pittsburgh District, Savannah District, Memphis District and Tulsa District are responding for this effort, in addition to support from throughout the enterprise.

We encourage all in the path of this storm to monitor conditions and updates from your local authorities.

USACE brings unique capabilities to emergency responses, but we are just one piece of a much larger US Army and United States Department of War team working to support our federal, state, and local partners.

Learn more from NOAA: National Oceanic & Atmospheric Administration: https://lnkd.in/e7PuDHdK

“Exploding trees” is a term that refers to two distinct phenomena: 

a rapid, loud cracking sound in trees during extreme cold (frost cracks), and the actual explosive dispersal of seeds by a tropical species known as the sandbox tree (or “dynamite tree”). 

Frost Cracking (Winter Phenomenon)

The “exploding trees” often referenced in news and social media during winter cold snaps are not actual explosions but a natural occurrence called frost cracking. 

• Cause: This happens when a tree’s outer layer of wood and bark contracts rapidly in sudden, severe cold, especially after being warmed by the sun. Simultaneously, the sap (which is mostly water) in the inner core freezes and expands. The immense pressure from the contracting outer layers against the expanding inner core causes the wood fibers to suddenly snap.
• Sound: The sudden release of tension produces a loud, sharp sound, often described as a gunshot or a crack, which can be heard across a quiet, frozen landscape.
• Vulnerable Trees: Trees with thin or soft bark, such as maples, birches, lindens, poplars, and ash, are more susceptible.
• Impact: While the cracks can be large and leave a scar, they are generally not fatal to the tree, which will typically heal over time. 

The Sandbox Tree (Tropical Phenomenon) 

A different, genuinely explosive phenomenon occurs with the fruit of the Hura crepitans species, native to tropical regions of North and South America. 

• Nickname: This tree is widely known by nicknames such as the “dynamite tree” or “monkey no-climb” due to its spiky trunk and explosive seed pods.
• Mechanism: When the large, pumpkin-shaped fruit capsules mature and dry, the internal tension becomes too great, causing them to burst open with a loud bang.
• Force and Speed: This explosion flings the hard, flattened seeds at speeds of up to 150-160 miles per hour (241-257 km/h) and distances of over 60 feet (18 meters). The resulting “shrapnel” can cause serious injury to people or animals nearby.
• Other Hazards: The Hura crepitans is considered one of the world’s most dangerous plants, also possessing a toxic sap that can cause a severe rash or blindness, and its trunk is covered in sharp spikes.