New! Sign up for our free email newsletter.
Science News
from research organizations

The Earth has a pulse -- a 27.5-million-year cycle of geological activity, researchers say

Analysis of 260 million years of major geological events finds recurring clusters 27.5 million years apart

Date:
June 18, 2021
Source:
New York University
Summary:
Geologic activity on Earth appears to follow a 27.5-million-year cycle, giving the planet a 'pulse,' according to a new study.
Share:
FULL STORY

Geologic activity on Earth appears to follow a 27.5-million-year cycle, giving the planet a "pulse," according to a new study published in the journal Geoscience Frontiers.

"Many geologists believe that geological events are random over time. But our study provides statistical evidence for a common cycle, suggesting that these geologic events are correlated and not random," said Michael Rampino, a geologist and professor in New York University's Department of Biology, as well as the study's lead author.

Over the past five decades, researchers have proposed cycles of major geological events -- including volcanic activity and mass extinctions on land and sea -- ranging from roughly 26 to 36 million years. But early work on these correlations in the geological record was hampered by limitations in the age-dating of geologic events, which prevented scientists from conducting quantitative investigations.

However, there have been significant improvements in radio-isotopic dating techniques and changes in the geologic timescale, leading to new data on the timing of past events. Using the latest age-dating data available, Rampino and his colleagues compiled updated records of major geological events over the last 260 million years and conducted new analyses.

The team analyzed the ages of 89 well-dated major geological events of the last 260 million years. These events include marine and land extinctions, major volcanic outpourings of lava called flood-basalt eruptions, events when oceans were depleted of oxygen, sea-level fluctuations, and changes or reorganization in the Earth's tectonic plates.

They found that these global geologic events are generally clustered at 10 different timepoints over the 260 million years, grouped in peaks or pulses of roughly 27.5 million years apart. The most recent cluster of geological events was approximately 7 million years ago, suggesting that the next pulse of major geological activity is more than 20 million years in the future.

The researchers posit that these pulses may be a function of cycles of activity in the Earth's interior -- geophysical processes related to the dynamics of plate tectonics and climate. However, similar cycles in the Earth's orbit in space might also be pacing these events.

"Whatever the origins of these cyclical episodes, our findings support the case for a largely periodic, coordinated, and intermittently catastrophic geologic record, which is a departure from the views held by many geologists," explained Rampino.

In addition to Rampino, study authors include Yuhong Zhu of NYU's Center for Data Science and Ken Caldeira of the Carnegie Institution for Science.


Story Source:

Materials provided by New York University. Note: Content may be edited for style and length.


Journal Reference:

  1. Michael R. Rampino, Ken Caldeira, Yuhong Zhu. A pulse of the Earth: A 27.5-Myr underlying cycle in coordinated geological events over the last 260 Myr. Geoscience Frontiers, 2021; 12 (6): 101245 DOI: 10.1016/j.gsf.2021.101245

Cite This Page:

New York University. "The Earth has a pulse -- a 27.5-million-year cycle of geological activity, researchers say." ScienceDaily. ScienceDaily, 18 June 2021. <www.sciencedaily.com/releases/2021/06/210618134009.htm>.
New York University. (2021, June 18). The Earth has a pulse -- a 27.5-million-year cycle of geological activity, researchers say. ScienceDaily. Retrieved April 14, 2024 from www.sciencedaily.com/releases/2021/06/210618134009.htm
New York University. "The Earth has a pulse -- a 27.5-million-year cycle of geological activity, researchers say." ScienceDaily. www.sciencedaily.com/releases/2021/06/210618134009.htm (accessed April 14, 2024).

Explore More

from ScienceDaily

RELATED STORIES