East coast vs. West: Hurricanes or earthquakes?

Combination photo of hurricane and earthquake images (Reuters)
The rivalry between East and West is classic. The differences between the coasts is like night and day. Along with everything else — culture, lifestyle, attitude, food, etc — the disasters on opposite ends of the country are vastly different.

Earthquakes happen at both ends of the country, of course. There was one in Montreal, back on October 10th, that registered as magnitude 4.5 — considered a 'light' quake on the Richter Scale. Over the past year, there has been a scattering of quakes along that same fault, plus around Nova Scotia, Newfoundland and Labrador, up in the north, a few in Ontario and even one near the Saskatchewan/Manitoba border. However, as glance at this map will reveal, the rest of the country can't hold a candle to the mountain and coastal regions in the west, when it comes to number and magnitude of earthquakes.

[ Related: Another earthquake rattles B.C. coast ]

Saturday's 7.7 magnitude quake in the Queen Charlotte Islands, and the resulting aftershocks, is an excellent example. There's not much of a difference between the numbers 4.5 and 7.7, except that the Richter scale is a 'logarithmic scale', so the values on the scale are powers of 10. Therefore, a 7.7 magnitude quake is nearly 1,600 times more powerful than a 4.5 magnitude quake. That's not to dismiss the impact of the Montreal quake, though, since any quake of magnitude 4.0 or greater has some chance of causing damage or injuries. It's just that the quakes on the west coast not only have a much greater chance of causing damage and injuries, but the damage and injuries can be far more severe.

One thing the west coast has never had to deal with, though, is a hurricane.

The east coast gets them every year. Sandy is the 18th named tropical cyclone so far this year, and is the fourth of this year's storms to impact somewhere on the east coast of North America. Why is the west coast spared?

[ Related: Monster storm leaves U.S. East Coast crippled; 30 dead ]

The west coast certainly gets enough rainfall, so it's not for lack of moisture. It's the temperature of the water that makes it a safe-haven for those looking to escape hurricanes and tropical storms.

The Gulf Stream is a warm ocean current that runs from the west coast of Africa, across the Atlantic to the Caribbean, then up the east coast from Florida to North Carolina, and then continues out to sea to the northeast from there until it mixes into the waters of the North Atlantic. It is this ocean current that keeps the water off the east coast plenty warm enough to sustain a tropical storm or hurricane, even as far north as the Atlantic provinces.

By comparison, the west coast has the Alaska Current. This is considered a warm ocean current — as it flows from south to north along the coast — however, the 'warm' for the Alaska Current originates from roughly the same latitude as the end of the Gulf Stream. Therefore it just can't deliver the amount of heat needed to sustain the kinds of storms seen in the east.

Also, any storm that did spin-up in the equatorial Pacific and tried to work its way up the west coast from there would slam into the southern end of the California Current — a cold ocean current that flows from north to south along the U.S. Pacific coast. The cold water in that current would quickly suck all the heat and energy out of such a bold storm.

Will the west coast of Canada ever see a tropical storm or hurricane? It's unlikely.

There are some 'Perfect Storm' scenarios that could see a tropical storm or hurricane reaching the California coast, but there are far too many factors working against such a storm for it to make the trip all the way to Vancouver.