Science
20 Mar 11
The post that was quoted here has been removedThe US Geological Survey collects all the eartquake data from across the world. They post it all on their site, twhitehead was quoting with regards to the number of 7+ earthquakes a year from the link i posted. Let's have a look -
2004 - 16 earthquakes 7 or above. Two of which were 9.1 and 8.1.
2003 - 15 earthquakes 7 or above. One of which was 8.3
2002 - 13 earthquakes 7 or above. None over 8.
2001 - 16 eartquakes 7 or above. One of which was 8.4
2000 - 15 earthquakes 7 or above. One of which was 8.0.
For that five year period i make that on average 1.25 earthquakes of a 7 magnitude or greater in a month.
All the data from 1990 to the present day can be found here -
http://earthquake.usgs.gov/earthquakes/eqarchives/year/
The post that was quoted here has been removedThe site I referenced says:
Based on observations since 1900.
This is in reference to their average yearly stats of:
8 and higher 1
7 - 7.9 15
So they are claiming slightly more than one a month since 1900 on average. You claim to know otherwise - so what are your stats?
The post that was quoted here has been removedWe have had 8 quakes of magnitude 7+ this year so far (three months) so we are well over average so far.:
http://earthquake.usgs.gov/earthquakes/eqarchives/year/2011/2011_stats.php
The Japan quake was preceded by a 7.2 two days before it and had two aftershocks over 7.0 ( 7.9 and 7.7) massive quakes in their own right.
Originally posted by twhiteheadThe events are taken from a list of historical tsunamis caused by earthquakes from a reference I had to hand ('Power of the Sea' by Bruce Parker, which provides a great overview of the relevant science related to extreme sea behaviour). As stated the evidence was anecdotal and I didn't intend to provide a detailed list of other events, nor do I have an agenda for not doing so (I just don't have the time 🙂). I've not tried to make any claims about possible statistical links.
I notice that nearly every event in your list includes a tsunami. Why is that? Tsunamis are not always caused by big quakes (in fact they are quite rare as far as I know).
So your list is really a subset of all big quakes and doesn't include many of the biggest.
So are the quakes in question hand picked to try and make a link, or is there an argument f ...[text shortened]... es, or those that cause tsunamis, or quakes avoid those apogess and perigees like the plague!
Incidently should we be concentrating on big quakes only, or instead a cumulative measure of total quake energy around the world per day?
Originally posted by ElleEffSeeeOK.
As stated the evidence was anecdotal and I didn't intend to provide a detailed list of other events, nor do I have an agenda for not doing so (I just don't have the time 🙂). I've not tried to make any claims about possible statistical links.
I just thought it was important to point out that you only listed tsunamis, which are only a small fraction of earthquakes - so if any link was to be made it would be between tsunamis and the moon and not between earthquakes and the moon.
Incidently should we be concentrating on big quakes only, or instead a cumulative measure of total quake energy around the world per day?
It very much depends on what the claimed link is. If we include smaller quakes then the shear quantity makes a detailed statistical analysis necessary to see anything.
In my opinion, if it is quite likely that tides and the moon do stress the earth slightly and so may affect when quakes that are going to happen anyway due to the stresses between continental plates actually happen. But that does not mean that they will happen more at a full moon or apogee or perigee. Maybe quite the opposite.
My main concern is to guard against the tendency of people to create statistics based on news reports without realizing that newsworthy quakes are a small fraction of actual quakes.