Homies:
Squid
JHKrpg
Minnie
Oblomovka
Yoohoo et al
Warrior Goddess
Yatima
Mama Pajama
Jo Spanglemonkey
Grace
Quilter
whump
Up for the Down Stroke
Brooklyn Days
elswhere
jennyalice
Riverbend
LJ friends

Kicking ass:
brokenclay
Wheelchair Dancer
Screw Bronze!
A Different Light
Chewing the Fat
Gimp Parade
Crip Power
Wheelie Catholic
Wheel World
Disability Studies blog
Wheelchair Diffusion

Favorites:
Pandagon
Bitch, Ph.D.
Angry Black Bitch
Feministe
This Is Zimbabwe
Arbusto de Mendacity
Brutal Women
Twisty
Body Impolitic
Mommybloggers
I, Asshole
Strip Mining for Whimsy
Zellar
Banubula
Random Redhead
Caracas Chronicles
El Universal
Venezuelanaylsis
The Loom
Pharyngula

More homies:
Claire Light
Sammest
Too Beautiful
Blogosity
Barak
Prentiss
NakedJen
Susie Bright
Tallie
Just Kristin
Brian
Mer
Realgurl
hjem
Not Calm Dot Com
Owlmonkey
Zombiegrrrl
KRON

More of my projects:
J. de Ibar.
Les Guérillères
Bookmania
Canadian beaver trade
Slut Manifesto
everything2 stuff
Cat Mustaches

More great stuff:
United Spinal Association
Disabilty Culture Watch
Green Fairy
Apophenia
Napsterization
BlogHer
Misbehaving Women
Broad Universe
Carl Brandon Society
Tiptree award
Locus
Words Without Borders
Center for the Art of Translation
Palabra Virtual
Poesía Diaria

Spanish dictionaries:
Google Language Tools
Yahoo spanish dictionary
DRAE
Onelook

stats



  • View My Stats

« parties parties parties! | Main | hilarity in the bunk bed! »

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

J

Tsunami speeds are only 500-1000 kph in open water, near shore they slow down to a few dozen kph:

http://www.oceansatlas.com/unatlas/issues/emergencies/tsunamis/tsunami.htm

The speed of an earthquake is 6-13 kilometers *per second*, or 21000-46000 kph:

http://vcourseware3.calstatela.edu/VirtualEarthquake/VQuakeExecute.html

badgerbag

Rook said that waves go faster through liquids than gases and faster t hrough solids than liquids. I asked if this is because of density? so would waves go faster through a more dense solid than a less dense? He babbled a little bit about strings and tension and then fell oddly silent.

Barak? perhaps you know...

J

Apparently not density, but stiffness. The stiffer (less elastic), the faster waves will propogate, the stretchier (more elastic) the slower. The more dense the substance for a given elasticity, the slower.

http://www.ncvs.org/ncvs/tutorials/voiceprod/equation/chapter5/

Barak

Um, It's confusing. There's lots of different kind of waves. And the medium that carries them does have some influence on the speed of propogation. "Stiffness" as J suggests, is a good measure of how fast waves propogate. If you've played a stringed instrument, you're familiar with the idea that if you tighten the string the pitch goes up, because the string gets stiffer and wave moves more quickly along the string, making a higher resonant frequency. Land is stiffer than water, which is stiffer than air.

Pressure waves tend to move faster than um 'longitudial' waves. In an earthquake on land you get both types of waves - those that displace in the direction that they are traveling (pressure waves) and those that displace perpendicular to the direction of travel. In the Loma Prieta quake in 1989, the north/south shaking (pressure waves) hit San Francisco several seconds earlier and harder than the east/west shaking (longitudinal waves).

In water the pressure waves don't amount to much, but the displacement of the land underneath the water moves a huge amount of water making a great big lumbering longitudinal wave (where the direction of displacement is up and down and the travel is horizontally). If the earthquake happens under very deep water, the entire column of water, maybe thousands of feet tall, over the earthquake is shifted up or down a few feet. As the wave gets closer to land the water gets much shallower, there is not as much water to displace, so the displacement gets larger and more energetic per volume of water. So a one foot displacement of land at the epicenter under a couple thousand feet of water, can cause tsunamis 40 feet high.

J

Apropos of what Barak said, the figure I cited for the propogation speed of earthquake waves was for P waves, not S waves.

The comments to this entry are closed.