More than 1,000 people died after a cyclone named Idai hit a portion of Africa in mid-March, a disaster this Third World area was neither prepared for or able to mitigate with its meager resources.
The wind blast devastated Mozambique’s fourth largest city of Beira. Neighboring Zimbabwe and Malawi were also affected. All three are in one of the world’s poorest areas, which most Americans can’t find, let alone pronounce, in southeast Africa.
Could such a natural disaster happen here, or worse? In Southern California we think in terms of an earthquake, not a cyclone. In the southeast its hurricanes. Cyclones (ala Dorothy’s trip to OZ) and flooding are the bane of Midwest and Mississippi waterways. Nature has a variety of ways to disrupt lives.
Not much thought has been given to any areas being wiped out by asteroids, which come in all shapes and threaten us infrequently, yet could have a greater effect than a cyclone or earthquake.
One recent report said there are around 800,000 known asteroids in the asteroid belt beyond Mars. There is no way yet to avoid or counter an asteroid coming our way. Yet we seem to be more concerned with nuclear disasters, which we can avoid.
To understand the situation, laymen need to acquaint themselves with space terminology. There are meteors, comets and asteroids. The first two are more for our enjoyment. A meteor is a small particle of matter seen by its incandescence caused by friction. Cast off by some far out body in space, it usually vaporizes. If it doesn’t, and enters Earth’s atmosphere, it is called a meteorite, as is a comet or asteroid from outer space. Such objects are credited with shaping the Earth and the Moon, which have the scars to show for it. Thousands of meteors become meteoroids. Weighing about a pound, they are thought to fall on our planet every year, and are rarely noticed.
Comets are made up of ice and dust, and usually leave a tail as they spin around space.
It’s asteroids entering our space, although fairly rare, that we need to be concerned about. Made up of solid stone and metal, the most feared ones show up near Earth about twice a century. Their shock wave on hitting or exploding can do major damage, although in the past century they haven’t taken any human lives. Their blasts or impacts are usually compared with many atomic bombs of the Hiroshima size. Asteroids as large as 13 feet enter Earth’s atmosphere about once a year. Most big ones explode in the upper atmosphere and the solids vaporize.
An asteroid, bursting in air or hitting and creating a crater (known as an impact event), can cause significant damage. The 1490 Ching-yang event in China is said to be the largest impact event on Earth in recorded history. 80 million trees were knocked down. No human fatalities were documented because of its remoteness. The most recent for widespread damage to forests was the Tunguska event in isolated Siberia in 1908. The harshest affecting humans was the Chelyabinsk meteor of 2013 which hit Russia’s Ural Mountains with 30 times the force of the Hiroshima bomb. The bulk of the blast, almost 100,000 feet high, was absorbed by the atmosphere. While 1,500 people sought medical treatment and 4,300 buildings were damaged, nobody was killed.
Should we be worried in Southern California? Drs. Eric B. Grosfils, a Pomona College professor of geology I heard recently, doesn’t seem to think so when you examine the odds.
Seventy percent of Earth’s surface is water. An asteroid hitting us would probably be equivalent of a 7-magnitude earthquake and leave a hole up to about 3 to 5 miles across, which would be quite a dent. Even if it hit offshore in the Pacific, the resulting tsunami would affect us, depending on location.
The floating piece of spacial matter that burst over Russia in mid-February 2013 injured 1,500 people and damaged 4,300 buildings. No one was killed. Had it been a few seconds later, it could have partially wiped out St. Petersburg or Moscow.
The late physicist Stephen Hawking wrote that an asteroid collision is the biggest threat to our planet. Scientists say we are totally unprepared for one.
However, Earth is such a pinhead in space, and we are such a pinhead on it, that the chances of us in Southern California being hit are highly remote. That’s why little has been done to protect us. The Jet Propulsion lab in Pasadena and NASA are working on better detection and ways to nudge a threatening asteroid out of the way of Earth contact. The uncertainties are great because we have little experiences with impact events caused by space matter, says Dr. Grosfils. Methods of prevention would take 5 to 30 years lead time. And we’ve yet to come up with anything on “when.”
We should be concentrating more on a big earthquake and better flood control across the nation.