Cottonwood and Balsam Poplar | Geophysical Institute
Nov 20, 2025 · The Klukwan giant holds the national record for black cottonwood diameter. Its nearest rival, a tree near Salem, Oregon, does hold the national height record. The Klukwan giant belies the …
Northern Tree Habitats - Geophysical Institute
Nov 20, 2025 · Interior Alaskan forests have only six native tree species: white spruce, black spruce, quaking aspen, balsam poplar, larch (tamarack) and paper birch. Northern Canadian forests have all …
Trees as Earthquake Fault Indicators | Geophysical Institute
Nov 6, 2025 · 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 earthquakes occurring …
The majesty and mystery of Alaska yellow cedar | Geophysical Institute
Jul 23, 2021 · A tree near one of our campsites had a crack at its base through which we could pass the folded saw. Yet the tree was still alive, with just one rope of cambium — the outer bark that …
The largest black spruce in Alaska | Geophysical Institute
Aug 16, 2010 · The tree leans uphill, and its trunk is 45 inches around. When I hugged it, I could barely clasp my hands together. The largest black spruce in Alaska is a lucky tree, because its neighbors to …
More on Why Tree Trunks Spiral | Geophysical Institute
Nov 6, 2025 · 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 here: Foliage …
Witches' Broom | Geophysical Institute
Nov 6, 2025 · Witches' broom on spruce trees is caused by a rust disease (a kind of fungus disease). The rust lives on the spruce tree throughout the year. Each spring, small yellow pustules appear on …
Burls and Human Cancer | Geophysical Institute
Nov 20, 2025 · Photograph of a section cut from a tree with 5 burls that simultaneously grew at the same level on the tree. Annual growth rings can be followed around the tree trunk at center and into each …
Black Spruce | Geophysical Institute
Nov 20, 2025 · Black spruce, unlike some other trees, tend to produce seed annually or nearly annually. They start bearing cones at about age 15. Once black spruce seed cones mature, they may remain …
Tropical Fossils in Alaska | Geophysical Institute
Nov 20, 2025 · 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 U.S. Geological …