New evidence has come to light about the asteroid that changed the course of Earth forever. Scientists have now identified that the Chicxulub asteroid, which ended dinosaur species on this planet, hit the surface in the spring in the Northern Hemisphere and autumn for the Southern Hemisphere. Read on to find out more about one of the most momentous impact disasters in Earth’s history and the season of its appearance.
Struck in Spring
The clues leading to this conclusion were found in the growth patterns preserved in the fossil bones of filter-feeding sturgeons and paddlefishes. These growth patterns indicate seasons similar to rings in tree trunks. Further evidence was found in the gills, where the impact debris lodged suggested it died instantly. A particular fish was also analyzed for carbon isotopes to determine how much zooplankton had been ingested. This information was useful as the feeding seasons peak during the spring and summer. Director of Smithsonian’s National Museum of Natural History Kirk Johnson has cast doubts on the importance of these conclusions as there was very little seasonality in the Cretaceous period.
The History
These fossils were gathered at Tanis in North Dakota, a late cretaceous deposit. The 66 million-year-old asteroid was responsible for not only ending the reign of dinosaurs on Earth, but also annihilating more than 76% of species. The Northwest Hemisphere species suffered a devastating blow as springtime is a crucial period for reproduction. Researchers have commented that this could be the reason why a faster recovery has been observed in some of the Southern Hemisphere species. Even though Kirk Johnson questions the validity of seasons in this discovery, he has stated that future research could test these ideas with Tanis serving as a reference. He also commented that this discovery opened avenues that had not been considered before.
There Have Been Nearly 300 Earthquakes at Yellowstone Recently
Many people have been watching for activity around Yellowstone due to the supervolcano that sits there. Fears grew in recent weeks that an eruption of that supervolcano could go off after almost 300 earthquakes occurred at Yellowstone. Despite fears, experts say we really shouldn’t worry about those earthquakes.
Seismic Proportions
In the month of May, there were a total of 288 earthquakes registered in the Yellowstone area, but it’s not a cause for concern, say scientists. More hype surrounded the possibility that the dormant supervolcano beneath Yellowstone was going to erupt, but that’s not the case. Yellowstone is actually one of the most seismically active areas of the United States, and these numbers are not uncommon.
Why So Many?
The main reason why there are so many earthquakes around Yellowstone is due to the network of tunnels and faults that surround the volcano. It’s where the famous geysers come from, and most of the earthquakes are not even felt by people. The diverse hydrothermal environment which supports hot springs, geysers, mud pots, and fumaroles create a hotbed of seismic activity.
Keeping The Pipes Clear
All of the seismic activity is actually a good thing for Yellowstone’s volcano. These little mini eruptions help to keep the network of tunnels free and clear. It’s better to have a series of mini eruptions than to wait for that pressure to build up into one big destructive one.
The earthquakes are related to the volcanic liquid that is transported around Yellowstone National Park. Several of the hot springs will actually begin to drain before a small eruption, giving experts a heads up that something is about to happen.
While an earthquake storm of over 300 might seem like a lot, there have been many more recorded in a year near Yellowstone. The record came in 1985 when there were over 3,000 earthquakes recorded during 12 months.