
Northern Tree Habitats - Geophysical Institute
Jan 29, 2026 · Interior Alaskan forests have only six native tree species: white spruce, black spruce, quaking aspen, balsam poplar, larch (tamarack) and paper birch. Northern Canadian …
Tropical Fossils in Alaska | Geophysical Institute
Jan 29, 2026 · A 20-inch fossil palm leaf that once waved over a tropical forest in Alaska 45-60 million years ago. The fossil was found in rocks near the Malaspina Glacier. Photo from the …
More on Why Tree Trunks Spiral | Geophysical Institute
Jan 29, 2026 · I eventually found a tree with a spiral lightning mark and it followed the spiral grain exactly. One tree, of course, proves nothing. "But why should the tree spiral? More speculation …
Tree Rings and History | Geophysical Institute
Jan 29, 2026 · A tree's age can be easily determined by counting its growth rings, as any Boy or Girl Scout knows. Annually, the tree adds new layers of wood which thicken during the …
Burls - Geophysical Institute
Dec 18, 2025 · Burls, spherical woody growths on the trunks of spruce, birch and other trees, are commonly found throughout wooded parts of Alaska.
The Pinhole: Nature's Lens | Geophysical Institute
Jul 10, 1972 · Sunlight passing through minor apertures between tree leaves is focused like the rays in a pinhole camera (and, just as with a simple lens, the image is upside-down).
The secret life of red squirrels | Geophysical Institute
Nov 27, 2024 · Stan Boutin has climbed more than 5,000 spruce trees in the last 30 years. He has often returned to the forest floor knowing if a ball of twigs and moss within the tree contained …
Bark Beetles in Spruce Trees | Geophysical Institute
Nov 20, 2025 · Bark beetles attack spruce trees in early summer. These brownish black beetles are common throughout Alaska and Yukon Territory where they kill trees by boring through the …
Trees as Earthquake Fault Indicators | Geophysical Institute
Jan 29, 2026 · Then using tree ring dating methods, it may be possible to date earthquakes occurring before historical records were kept. The ability to identify and date very large …
The Kodiak Treeline | Geophysical Institute
Jan 29, 2026 · Spruce trees planted on the islands by the Russians in 1805 are doing just fine and reseeding themselves naturally, although the total tree population hardly amounts to a forest. …