Well, there was a tsunami warning for west coast

[Balta1701]

That same area had a minor tsunami in 1964 which killed 11 people.

The 1964 Tsunami happened because of a magnitude 9 quake in Alaska.

[Balta1701]

Wow, the earth is really going nuts.  SD earthquake at 5.6, this earthquake at 7, and the Chilean quake at over 7.

 

The earth must look like a tuning fork right now.

 

Jim maybe you know this, could this be secondary effects of the Indonsesian quake, basically shaking the earth so hard, that some of the other faults of the world start to give way?  And also do you think we could see some more volcanic activity that could be the result of, or a contributing cause to this quake activity?

 

No, there is no relation between this quake and the Indonesian quake.

 

While it may seem like every now and then there is a lot of seismic activity, what's actually happening is that you just don't always hear about them unless they're huge or cause a lot of devastation. Pick any growing mountain range, and you find yourself seeing a few magnitude 7 events per year. But if they happen in completely isolated areas, there's no reason for press to cover them.

 

I think a graph like the one that follows is a very handy graph. It shows an estimate of the frequency of earthquakes per year based on the magnitude of those events. If you look, you'll see that in an average year, the planet will experience 1 earthquake of magnitude 8, 10-20 earthquakes of magnitude 7, 100+ earthquakes of magnitude 6, and nearly 1000 earthquakes of magnitude 5.

 

A magnitude 9 event happens on average once every 10 years or so, so those events are rare in and of themselves and are worth special attention when they happen, but the fact that you're seeing more earthquake coverage on the news does not indicate that the earth is going wild or anything like that.

 

And in terms of the volcano question...the amount of energy released by the Sumatran quake is actually essentially negligible compared to the heat lost by Earth every year. Earth is a very hot body, and it is trying to get rid of that energy as fast as it can. Some of it is dissipated by earthquakes. Lots more is dissipated by heat flow through the surface and worldwide volcanic activity. The energy of 1 earthquake is basically a drop in the bucket of energy displacement. So no, there would be no expected major change in volcanic activity from 1 earthquake.

 

Image referred to above:

 

(From Physics today)

[FlaSoxxJim]

Dang, Balta, I had forgot that you mentioned you were a GeoGeek a few days ago. Thanks for the rundown.

 

Do you know what is really cool from what you shared? It's striking that the logarithmic nature of the Richter Scale (a 7 being 10x stronger than a 6, etc, for the non-GeoGeeks) is also so beautifully reflected in the frequency of occurence of quakes of each magnitude. In one year you'll typically see 1 magnitude 8, 10 mag 7s, 100 mag 6s. And going the other way, a magnitude 9 event - 10 times stronger than a magnitude 8 - is also 10x less frequent. Wild symmetry. The pH scale is the only other log10 scale I have much familiarity with, and I don't believe it has nearly that kind of perfect symmetry as you go either up or down from nautrality at pH 7.

 

[/done being a nerd... for now]

[SoxFan1]

That same area had a minor tsunami in 1964 which killed 11 people.

There is no such thing as a minor tsunami lol. It's callud a tsunami for a reason.

 

Little know fact: My baseball nickname is Tsunami because I sweat a lot when I pitch.

[FlaSoxxJim]

There is no such thing as a minor tsunami lol. It's callud a tsunami for a reason.

 

Little know fact: My baseball nickname is Tsunami because I sweat a lot when I pitch.

But just like there are categories of earthquakes and hurricanes, there are tsunamis of varying magnitude. Also, the further removed a coastline is from the epicenter, the smaller the tsunami is goin to be when it arrives. I'd say casually categorizing tsunami events as major or minor is acceptable.

[SoxFan1]

But just like there are categories of earthquakes and hurricanes, there are tsunamis of varying magnitude.  Also, the further removed a coastline is from the epicenter, the smaller the tsunami is goin to be when it arrives.  I'd say casually categorizing tsunami events as major or minor is acceptable.

Wow, I didn't know that. Enlighten me.........how do the ycategorize tsunami's?

[FlaSoxxJim]

Wow, I didn't know that. Enlighten me.........how do the ycategorize tsunami's?

I'm not the expert – perhaps Balta will chime in – but I don't know, how about MEASURING THE HEIGHT OF THE WAVE?!? You know, smaller waves = minor tsunami and bigger waves = major tsunami..

[Balta1701]

Wow, I didn't know that. Enlighten me.........how do the ycategorize tsunami's?

 

As far as I know, there's no richter-scale type classification system for tsunami...what's usually done is that the height of tsunami is estimated based on how high up the water goes at a particular distance from the earthquake epicenter.

 

Just for an example...the Sumatran tsunami actually did strike New York and Washington D.C. It's just that at that distance, it was hard to discern amongst all the other waves.

[FlaSoxxJim]

OK, it started bugging me that there had to be defined categories of tsunamis, and a visit to NOAA's International Tsunami Information Center suggested that was the case. Certainly not as cut and dried as storm or earthquake magnitude categories because so much depends on water depth and distance from the source etc., but lots of different tsunami categories:

 

atmospheric tsunami --

Tsunami-like waves generated by a rapidly moving atmospheric pressure front moving over a shallow sea at about the same speed as the waves, allowing them to couple.

 

internal tsunami --

Tsunami wave manifested as an internal wave and traveling along a thermocline.

 

local tsunami --

A tsunami which its destructive effects are confined to coasts within a hundred km, of the source, usually an earthquake and sometimes a landslide.

 

microtsunami --

A tsunami of such small amplitude that it must be observed instrumentally and is not easily detected visually. [The very definition of a very, very 'minor' tsunami, no?]

 

near-field or local tsunami --

A tsunami from a nearby source, generally less than 200 km away. A local tsunami is generated by a small earthquake, a landslide or a pyroclastic flow.

 

Pacific-wide tsunami --

A tsunami capable of widespread destruction, not only in the immediate region of its generation, but across the entire Pacific Ocean. [i'd call this type a major tsunami]

 

regional tsunami --

A tsunami capable of destruction in a particular geographic region, generally within about 1000 km of its source. Regional tsunamis also occasionally have very limited and localized effects outside the region.

 

teletsunami or distant tsunami --

A tsunami originating from a distant source, generally more than 1000 km away.

 

Looks like these are the mac daddy tsunamis: Far less frequent, but potentially much more hazardous are Pacific-wide or distant tsunamis. These occur when the disturbance that generates the tsunami is sufficiently great. Usually starting as a local tsunami that causes extensive destruction near the source, these waves continue to travel across the entire ocean basin with sufficient energy to cause additional casualties and destruction on shores more than a thousand km from the source. In the last two hundred years, there have been at least seventeen destructive Pacific-wide tsunamis.