RE: Earthquakes
The West Eifel volcanic field (SW of Bonn, Germany) is not far from NL and the last spectacular eruption there was about 9000 or so years ago (rather recently in geological terms). And there have been other significant earthquakes in the region in recorded history. The Lisbon quake in the 18th century was felt across much of Europe. > -Original Message- > From: Jeroen van Aart [mailto:jer...@mompl.net] > Sent: Wednesday, March 24, 2010 3:32 PM > To: NANOG list > Subject: Re: Earthquakes > > Owen DeLong wrote: > > I've been through more than one quake in the 5.2-5.5 range, so, > perhaps they are > > rare in the Netherlands (6 million years or so), but, in California > they are much more > > frequent, perhaps 5-7 years or so. > > Well, 6 million years was a "slight" exaggeration to get a point > across. > The Netherlands doesn't really have any quakes due to faultlines (there > aren't any). But it does have the occasional quake due to coal/gas > mining. Where the ground compacts or something like it.
Re: Earthquakes
On 2010-03-24, at 13:12, Ken Gilmour wrote: > We had a 6.2 last year in Costa Rica... We immediately regretted where we > had placed our racks and are almost finished a project to move them to a > concrete floor (rather than that compressed cardboard stuff). Lost a lot of > hard drives that day! We regularly have quakes between the 4-5 region here. > By regularly, i mean a minimum of 5 times a year in different parts of the > country. If there is interest in data centre provisioning or construction, disaster planning or inside/outside plant strategies intended to mitigate damage by earthquakes then the NZNOG list might well be a good English-language place to get some advice. Earthquakes of magnitude 4 and up happen pretty regularly (several times per week is common). http://www.geonet.org.nz/earthquake/quakes/recent_quakes.html http://www.nznog.org/ Joe
RE: Earthquakes
> -Original Message- > From: Owen DeLong [mailto:o...@delong.com] > Sent: Wednesday, March 24, 2010 11:48 PM > To: Jeroen van Aart > Cc: NANOG list > Subject: Re: Earthquakes > > > On Mar 24, 2010, at 3:32 PM, Jeroen van Aart wrote: > > > Owen DeLong wrote: > >> I've been through more than one quake in the 5.2-5.5 range, so, > perhaps they are > >> rare in the Netherlands (6 million years or so), but, in California > they are much more > >> frequent, perhaps 5-7 years or so. > > > > Well, 6 million years was a "slight" exaggeration to get a point > across. The Netherlands doesn't really have any quakes due to > faultlines (there aren't any). But it does have the occasional quake > due to coal/gas mining. Where the ground compacts or something like it. > > LOL @ NL creating artificial earthquake faults because they're Jealous > of California's natural seismic events. ;-) Sorry for being jealous ;) At least we create them and in California they just happen. Mark
Re: Earthquakes
On Mar 24, 2010, at 3:32 PM, Jeroen van Aart wrote: > Owen DeLong wrote: >> I've been through more than one quake in the 5.2-5.5 range, so, perhaps they >> are >> rare in the Netherlands (6 million years or so), but, in California they are >> much more >> frequent, perhaps 5-7 years or so. > > Well, 6 million years was a "slight" exaggeration to get a point across. The > Netherlands doesn't really have any quakes due to faultlines (there aren't > any). But it does have the occasional quake due to coal/gas mining. Where the > ground compacts or something like it. LOL @ NL creating artificial earthquake faults because they're Jealous of California's natural seismic events. ;-) Owen
Re: Earthquakes
Michael Thomas wrote: Something to keep in mind is that raw magnitude isn't the whole story. The ground composition is *much* more important when it comes to destructiveness. A 5.0 earthquake in the Netherlands might be extremely damaging because of liquifaction. Yes the one I mentioned from the late 80s damaged buildings quite a bit around the epi centre in the SE. That would be damage such as falling roof tiles and cracks in walls. But then the Dutch do build a lot with brick and mortar. That's a big no no in places like California.
Re: Earthquakes
Owen DeLong wrote: I've been through more than one quake in the 5.2-5.5 range, so, perhaps they are rare in the Netherlands (6 million years or so), but, in California they are much more frequent, perhaps 5-7 years or so. Well, 6 million years was a "slight" exaggeration to get a point across. The Netherlands doesn't really have any quakes due to faultlines (there aren't any). But it does have the occasional quake due to coal/gas mining. Where the ground compacts or something like it.
Re: Earthquakes
Something to keep in mind is that raw magnitude isn't the whole story. The ground composition is *much* more important when it comes to destructiveness. A 5.0 earthquake in the Netherlands might be extremely damaging because of liquifaction. Also: California since we get quakes all the time, our rock is more "shattered" which damps the seismic waves. Back east, on the other hand, the bedrock is more solid which is why the New Madrid earthquakes traveled so far (ringing bells in Boston, IIRC). Of course New Madrid were huge earthquakes by any standard. Mike On 03/24/2010 01:20 PM, Owen DeLong wrote: In California, 4s are a regular occurrence and we have 2-3s every day. I rarely notice anything less than a 5, and, often do not notice up to a 5.5 in my area. The worst quake I have personally experienced was the 1989 Loma Prietta quake which was a 7.9 IIRC. It caused some significant damage to some substandard (by modern measure, not when they were built) structures, most notably the bay bridge and the cypress and embarcadero elevated freeways and a brick-and-morter (literally) mall in Santa Cruz. Other than that, the damage from the 7.9 was minimal outside of a relatively contained zone rather close to the epicenter. I've been through more than one quake in the 5.2-5.5 range, so, perhaps they are rare in the Netherlands (6 million years or so), but, in California they are much more frequent, perhaps 5-7 years or so. Owen On Mar 24, 2010, at 12:31 PM, Jeroen van Aart wrote: I saw a recent(-ish) short thread about a mag. 4 quake in the SF Bay Area. This http://earthquake.usgs.gov/earthquakes/recenteqsus/Maps/US2/36.38.-123.-121.php should provide with everything you need to know. I check it on a daily basis and it's been rather quiet the past week or 2 or so. Actually I guess it's been rather quiet ever since the 1989 quake, but then a year or so ago I woke up in the morning from some rattling doors so I guess it all depends on your perspective. So far the "worst" quake ever I experienced was in the Netherlands back around 1988. Magn. 5.2 or something. Which is interesting considering these happen like once every 6 million years or thereabouts ;-) Actually I slept through it so I don't know if one can call it "experiencing". Greetings, Jeroen
RE: Earthquakes
When I was living in San Jose/Sunnyvale and we had a 5.2 in 2001? (can't remember the date, was a bit ago). The only effect I felt from it was as if someone had taken the back of my chair and pushed it forward, that was about it. Of course at the same time there was a large Earthquake in Turkey being broadcast on the News, so thought it was just me, but when it came on the news a few minutes later Since than I believe there have been several 5.0+ in that area, obviously none have been as significant as the one in 1988, but I think its only a matter of time till a large one occurs. Regards, -Joe Blanchard
Re: Earthquakes
In California, 4s are a regular occurrence and we have 2-3s every day. I rarely notice anything less than a 5, and, often do not notice up to a 5.5 in my area. The worst quake I have personally experienced was the 1989 Loma Prietta quake which was a 7.9 IIRC. It caused some significant damage to some substandard (by modern measure, not when they were built) structures, most notably the bay bridge and the cypress and embarcadero elevated freeways and a brick-and-morter (literally) mall in Santa Cruz. Other than that, the damage from the 7.9 was minimal outside of a relatively contained zone rather close to the epicenter. I've been through more than one quake in the 5.2-5.5 range, so, perhaps they are rare in the Netherlands (6 million years or so), but, in California they are much more frequent, perhaps 5-7 years or so. Owen On Mar 24, 2010, at 12:31 PM, Jeroen van Aart wrote: > I saw a recent(-ish) short thread about a mag. 4 quake in the SF Bay Area. > This > http://earthquake.usgs.gov/earthquakes/recenteqsus/Maps/US2/36.38.-123.-121.php > should provide with everything you need to know. > > I check it on a daily basis and it's been rather quiet the past week or 2 or > so. Actually I guess it's been rather quiet ever since the 1989 quake, but > then a year or so ago I woke up in the morning from some rattling doors so I > guess it all depends on your perspective. > > So far the "worst" quake ever I experienced was in the Netherlands back > around 1988. Magn. 5.2 or something. Which is interesting considering these > happen like once every 6 million years or thereabouts ;-) > Actually I slept through it so I don't know if one can call it "experiencing". > > Greetings, > Jeroen
RE: Earthquakes
When I lived in the Bay Area, I noticed that 4.x quakes only tended to shake the room ever-so-slightly. You could only really tell if they happened, if you happened to see liquid in a glass moving. Leah -Original Message- From: Ken Gilmour [mailto:ken.gilm...@gmail.com] Sent: Wednesday, March 24, 2010 1:12 PM To: Jeroen van Aart Cc: NANOG list Subject: Re: Earthquakes We had a 6.2 last year in Costa Rica... We immediately regretted where we had placed our racks and are almost finished a project to move them to a concrete floor (rather than that compressed cardboard stuff). Lost a lot of hard drives that day! We regularly have quakes between the 4-5 region here. By regularly, i mean a minimum of 5 times a year in different parts of the country. Interesting, the epicenter was only a few km (about 30) from the capital city and no communications were knocked out (except within a 6 km radius of the epicenter which was affected more by mud slides knocking things over. Here's what it looked like... http://www.youtube.com/watch?v=F8udXyyqUiw On 24 March 2010 13:31, Jeroen van Aart wrote: > I saw a recent(-ish) short thread about a mag. 4 quake in the SF Bay Area. > This > http://earthquake.usgs.gov/earthquakes/recenteqsus/Maps/US2/36.38.-123.- 121.php > should provide with everything you need to know. > > I check it on a daily basis and it's been rather quiet the past week or 2 > or so. Actually I guess it's been rather quiet ever since the 1989 quake, > but then a year or so ago I woke up in the morning from some rattling doors > so I guess it all depends on your perspective. > > So far the "worst" quake ever I experienced was in the Netherlands back > around 1988. Magn. 5.2 or something. Which is interesting considering these > happen like once every 6 million years or thereabouts ;-) > Actually I slept through it so I don't know if one can call it > "experiencing". > > Greetings, > Jeroen > > This email may contain confidential and privileged material for the sole use of the intended recipient. Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender by reply email and delete all copies of this message.
Re: Earthquakes
We had a 6.2 last year in Costa Rica... We immediately regretted where we had placed our racks and are almost finished a project to move them to a concrete floor (rather than that compressed cardboard stuff). Lost a lot of hard drives that day! We regularly have quakes between the 4-5 region here. By regularly, i mean a minimum of 5 times a year in different parts of the country. Interesting, the epicenter was only a few km (about 30) from the capital city and no communications were knocked out (except within a 6 km radius of the epicenter which was affected more by mud slides knocking things over. Here's what it looked like... http://www.youtube.com/watch?v=F8udXyyqUiw On 24 March 2010 13:31, Jeroen van Aart wrote: > I saw a recent(-ish) short thread about a mag. 4 quake in the SF Bay Area. > This > http://earthquake.usgs.gov/earthquakes/recenteqsus/Maps/US2/36.38.-123.-121.php > should provide with everything you need to know. > > I check it on a daily basis and it's been rather quiet the past week or 2 > or so. Actually I guess it's been rather quiet ever since the 1989 quake, > but then a year or so ago I woke up in the morning from some rattling doors > so I guess it all depends on your perspective. > > So far the "worst" quake ever I experienced was in the Netherlands back > around 1988. Magn. 5.2 or something. Which is interesting considering these > happen like once every 6 million years or thereabouts ;-) > Actually I slept through it so I don't know if one can call it > "experiencing". > > Greetings, > Jeroen > >
