Science news: Melting glaciers and Alaska earthquakes, chemistry triggers landslides, Zealandia switch, Beirut blast in 2020

Glaciers such as the Yakutat in Southeast Alaska, shown here, have been melting since the end of the Little Ice Age, influencing earthquakes in the region. Photo: Sam Herreid

Recent discoveries about our planet, its rocks, and other “stone” topics

(Photo above) In 1958, a magnitude 7.8 earthquake triggered a rockslide into Southeast Alaska’s Lituya Bay, creating a tsunami that ran 1,700 feet up a mountainside before racing out to sea. Researchers now think the region’s widespread loss of glacier ice helped set the stage for the quake

Mass movements like a landslide in the picture cause considerable damage year after year. Photo: Kieffer / TU Graz/DCNA
Mass movements such as landslides and hill-slope debris flows cause billions of euros in economic damage around the world every year. Now, a team of Austrian scientists identified for the first time the chemical influencing factors and triggers for recurrent mass movements in fine-grained sediments

Moraines constructed during repeated advance-retreat cycles of one of the glaciers that extended out from the Southern Alps in New Zealand during the last ice age. Photo: Aaron PutnamThe origins of ice age climate changes may lie in the Southern Hemisphere, where interactions among the westerly wind system, the Southern Ocean and the tropical Pacific can trigger rapid, global changes in atmospheric temperature, according to an international research team. The mechanism is dubbed the Zealandia Switch  

The ionospheric disturbance caused by an explosion can be detected by differential ionospheric delays of microwave signals of two carrier frequencies from global navigation satellite system (GNSS) satellites. Source: Bhaskar Kundu, et al. Scientific Reports. February 2, 2021
A 2020 explosion in Lebanon’s port city of Beirut led to a southward-bound, high-velocity atmospheric wave that rivaled ones generated by volcanic eruptions. The blast is considered one of the most powerful non-nuclear, man-made explosions in human history.

(23.02.2021, USA: 03.23.2021)