Can Big Earthquakes Disrupt World Weather?

by |April 28, 2011

The recent earthquake in Japan shifted the earth’s axis by half a foot. You may be wondering if that’s enough to change earth’s weather. No, not really, says Jerry McManus, a climate scientist at Columbia’s Lamont-Doherty Earth Observatory.

Earthquakes unleash a tremendous amount of energy, but not enough to upset the energy balance of earth’s atmosphere and oceans, which drive weather patterns in the short term, he says. Larger shifts of the planet’s rotational axis happen each year due to the fluctuating mass of earth’s atmosphere and oceans without changing the weather. These natural variations can push earth’s axis up to 39 inches, far more than the Japan earthquake’s 6.5-inch nudge or the 2010 Chile earthquake’s 2.8-inch shift.

Those shifts are tiny compared to long-term, cyclical shifts in earth’s movement that can raise or lower the planet’s thermostat. The planet currently leans at a 23.5 degree angle as it circles the sun, causing winter at one end of the globe and summer at the other, as its orientation toward the sun redistributes the amount of sunlight falling on each hemisphere annually. But the seasons can be greatly intensified depending on variations in earth’s tilt over long timescales. Every 41,000 years or so, earth’s tilt shifts about a degree in each direction—the equivalent of nearly 70 miles. At its highest tilt—24.5 degrees—more sunlight falls on the poles; at its lowest—22.1 degrees—more light falls on the equator.

Two other astronomical cycles shape earth’s climate: the changing shape of its elliptical path around the sun every 100,000 years or so, and the shifting wobble of its axis—much like a spinning top—on average, every 21,000 years. All three cycles are caused by the gravitational tug of the moon and the planets in our solar system.

In the first half of the 20th century, Serbian mathematician Milutin Milankovitch painstakingly calculated how all three cycles—respectively referred to as obliquity, eccentricity and precession influence the amount of seasonal sunlight falling over the planet. Though the calculations that were his life’s work can now be made in a few minutes by a student using a laptop, the name “Milankovitch” still describes the cycles that are so fundamental to earth’s climate.

Get our newsletter

I'd like to get more stories like this.
Email address
Secure and Spam free...

3
Leave a Reply

avatar
3 Comment threads
0 Thread replies
0 Followers
 
Most reacted comment
Hottest comment thread
3 Comment authors
KayTravis GillespieMark Reimers Recent comment authors
  Subscribe  
newest oldest most voted
Notify of
Mark Reimers
Guest

I hear counter arguments all the time about how the natural cycles of earth account for the global warming we have experienced over the past century. As discussed in the article, these cycles are quite long when compared to the very short time frame of the recent intense global warming. We’re talking 10’s of thousands of years vs a couple of decades. Anyway, it’s comforting to know that even the most powerful earthquake won’t send us into the next ice age.

Cheers!

Travis Gillespie
Guest
Travis Gillespie

Another thought on “Can Big Earthquakes Disrupt World Weather?” The oceans currents were changed by the last big earthquake in Japan when part of it fell into the ocean. The ocean currents do affect the worlds weather, but how much will this affect it? I am just curious and seeking answers.

Respectfully yours.

Kay
Guest
Kay

Of course the weather did not change, but since our position within the weather patterns changes from these events wouldn’t this affect our perception of the weather? In other words, if I move my thermometer from one location to another in my yard and take readings over a period of time, they would not produce the same average as when it was elsewhere in my yard. Also, the earthquake in Japan caused a huge collapse of an ice shelf, so is it possible that not all scientists, or weather reporters, are crediting the earthquake but instead are crediting climate change… Read more »