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  1. Northern Tree Habitats - Geophysical Institute

    Feb 19, 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 forests have all …

  2. Cottonwood and Balsam Poplar | Geophysical Institute

    Feb 19, 2026 · 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 …

  3. Tropical Fossils in Alaska | Geophysical Institute

    Feb 19, 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 U.S. Geological …

  4. More on Why Tree Trunks Spiral | Geophysical Institute

    Feb 12, 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 here: …

  5. Burls - Geophysical Institute

    Feb 12, 2026 · Burls, spherical woody growths on the trunks of spruce, birch and other trees, are commonly found throughout wooded parts of Alaska.

  6. 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 newborn red …

  7. Witches' Broom | Geophysical Institute

    Feb 19, 2026 · 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 …

  8. Orange trees in the Alaska Range | Geophysical Institute

    Sep 3, 2020 · It was a tree disease known as spruce needle rust, which infects only the current year’s needles of white, black and Sitka spruce trees. The orange powder is composed of millions of tiny …

  9. Trees as Earthquake Fault Indicators | Geophysical Institute

    Feb 19, 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 earthquakes occurring …

  10. 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 …