Archiv: evolution / extinctions / new species / periodes


21.02.2021 - 13:30 [ Sciencealert.com ]

Earth’s Magnetic Field Could Be Changing Much Faster Than We Ever Realised

(08.07.2020)

Quicker changes in direction seem to coincide with a local weakening of the magnetic field, the new research found. One shift in particular was highlighted: a movement of 2.5 degrees per year 39,000 years ago, right after the most recent Laschamp excursion flip, when the Earth’s magnetic field was weakened around the west coast of Central America.

21.02.2021 - 13:05 [ ScienceNews.org ]

50 years ago, scientists named Earth’s magnetic field as a suspect in extinctions

Excerpt from the November 21, 1970 issue of Science News

21.02.2021 - 12:40 [ Science Magazine ]

A global environmental crisis 42,000 years ago

(19.02.2021)

We find that geomagnetic field minima ~42 ka, in combination with Grand Solar Minima, caused substantial changes in atmospheric ozone concentration and circulation, driving synchronous global climate shifts that caused major environmental changes, extinction events, and transformations in the archaeological record.

21.02.2021 - 12:35 [ CNN ]

Reversal of Earth’s magnetic poles may have triggered Neanderthal extinction — and it could happen again

(19.02.2021)

Some 42,000 years ago, in an event known as the Laschamp Excursion, the poles did just that for around 800 years, before swapping back — but scientists were unsure exactly how or if it impacted the world.

Now, a team of researchers from Sydney’s University of New South Wales and the South Australian Museum say the flip, along with changing solar winds, could have triggered an array of dramatic climate shifts leading to environmental change and mass extinctions.

22.01.2020 - 22:02 [ Dr. Jessie Christiansen ‏/ Twitter ]

I have always been interested in galactic archaeology, but I don’t think this is what they meant. Did you know that dinosaurs lived on the other side of the Galaxy?

(28.08.2019)

02.01.2020 - 16:57 [ Dr. Jessie Christiansen ‏/ Twitter ]

I have always been interested in galactic archaeology, but I don’t think this is what they meant. Did you know that dinosaurs lived on the other side of the Galaxy?

(28.08.2019)

15.11.2019 - 15:00 [ businessinsider.fr ]

A NASA scientist’s incredible animation shows how dinosaurs roamed the Earth on the other side of the Milky Way galaxy

Our sun orbits the galaxy’s center, so many dinosaurs roamed the Earth while the planet was on the other side of the Milky Way.

Our solar system’s orbit keeps us just the right distance from the galaxy’s chaotic center for life to exist.

15.11.2019 - 12:27 [ Dr. Jessie Christiansen ‏/ Twitter ]

I have always been interested in galactic archaeology, but I don’t think this is what they meant. Did you know that dinosaurs lived on the other side of the Galaxy?

30.05.2019 - 16:11 [ arxiv.org ]

Hypothesis: Muon Radiation Dose and Marine Megafaunal Extinction at the end-Pliocene Supernova

(November 2018)

Considerable data and analysis support the detection of one or more supernovae (SNe) at a distance of about 50 pc, ∼2.6 million years ago. This is possibly related to the extinction event around that time and is a member of a series of explosions that formed the Local Bubble in the interstellar medium. We build on previous work, and propagate the muon flux from SN-initiated cosmic rays from the surface to the depths of the ocean. We find that the radiation dose from the muons will exceed the total present surface dose from all sources at depths up to 1 km and will persist for at least the lifetime of marine megafauna. It is reasonable to hypothesize that this increase in radiation load may have contributed to a newly documented marine megafaunal extinction at that time.

30.05.2019 - 15:55 [ New York Times ]

STUDY HINTS EXTINCTIONS STRIKE IN SET INTERVALS

(11. Dezember 1983)

At a conference on mass extinctions, held in August at Northern Arizona University in Flagstaff, Dr. Sepkoski said the timing of these events suggested that “there is indeed a statistically significant periodicity in the observed distribution of events of mass or accelerated extinction over the last 250 million years.“ Search for Answers

He confessed this “stumped“ him and Dr. Raup, saying: “We are aware of no documented process with a cycling time approximately 26 million years. But with that long a cycle, we suspect that the forcing agent will not be terrestrial but rather solar or galactic.“

30.05.2019 - 15:49 [ Harvard.edu ]

Cosmic-ray volleys from the Galactic Center and their recent impact on the earth environment

Authors: Laviolette, P. A.
Journal: Earth, Moon, and Planets (ISSN 0167-9295), vol. 37, March 1987, p. 241-286.