Jump to content
Science Forums

Recommended Posts

Posted
When a tsunami occurs the tide runs out as it did in the 2002 Papua, New Guinea quake that caused a tsunami. It appears the water first receded from the shore. Then the flow reversed and a tidal wave overwhelmed the low-lying coastal region. With the exception of an ocean floor cave in, the types of faults you have mention would not cause a tsunami. That is why I call it an expansion quake. A void must be created for the water to recede from the shore then return with a vengeance.

 

You can think of the vibrations of the tsunami or the quake that started it as an example of a simple harmonic oscillator. In this example there will be highs and lows. If you had an open mind, I would suggest you go look up a wiki on tsunami. I suspect this might be the opposite case based on some of your previous posts.

 

maddog

 

you are on the right track maddog, on more than one count. :dog: woof! :lol: anyway, let me expand on the withdrawing of shorewater, tsunamis, and oscillations.

 

when the dip-slip fault breaks causing the quake and the uplifted side of the fault forces a column of non-compressible water upward, the water at the surface that surrounds the lifted column drops, creating a roughly circular depressed trough. the oscillations then cycle, just as you see when you cast a stone into a pond. because this oscillation starts offshore, and because the trough is of necessity closer to shore -the uplift being inward of the trough-, it is a depression of the oscillating wave that first reaches shore and so the water at the shore is first drawn out.

 

a tsunami wave, while displacing a large volume of water, is not very high in its crest, but the wavelength is quite large. the longer the section of the fault that breaks, the longer the wavelength created and the greater the volume displaced. ships at sea (well, the people on them) may not even notice the wave as it passes beneath them. when this low-height long-wavelength wave crest reaches the shore, it piles up against the shore's slope and rises. because of its long length however, it does not break like normal shore waves and continues to build in height and flow inland.

 

Ocean in Motion: Waves - Characteristics

Posted (edited)
I would remind you Turtle that gravity is always a bidirectional acceleration. In teaching this subject professors get sloppy and make it a unidirectional acceleration because Earth is so much larger than any satellite we launch. But it is always a bidirectional acceleration.

elijah,

 

I don't think you were really paying attention when listening to those professors. It is likely what these instructors were attempting to tell you was the breakdown of the actual vector (direction of arrow) into its resultant vectors to align with the reference coordinate system. Yes, some generic direction in 3-space would break down into 3 separate vectors along each coordinate axis. On the mathematics, I have rarely observed professors being lax in this area. Interpretation, yes, they get sloppy (this is usually when the "hand waving" occurs).

 

As for multi-directional "whatever" you would have to be talking GR where Tensors are used (spacetime is [at least] 4-dimensional), so 4 or more directions are used (depending on whether you throw in a wandering string theory, etc). Beyond that, you need to tell your doctor to lighten up on the medication, because they're causing you delusions! :blink:

 

maddog

Edited by maddog
Guest MacPhee
Posted

quite simply, you have no idea what you are talking about. stop posting this pseudo-scientific hogwash to our board. :naughty:

 

Isn't it a bit rash to dismiss new ideas as "pseudo-scientific hogwash"?

The ideas of Copernicus, Galileo, Newton, Lavoiser, Darwin, and Wegener were rubbished as "hogwash" in their time.

 

But they proved to be right in the end! So, tread carefully, avoid emotive disparagement. Refute scientifically.

Posted

Isn't it a bit rash to dismiss new ideas as "pseudo-scientific hogwash"?

The ideas of Copernicus, Galileo, Newton, Lavoiser, Darwin, and Wegener were rubbished as "hogwash" in their time.

 

But they proved to be right in the end! So, tread carefully, avoid emotive disparagement. Refute scientifically.

 

i have not been rash. i have read elijah's posts here and in other threads over several weeks and he is no copernicus, nor galileo, nor newton, nor darwin, nor wegener, nor lavoiser, nor darwin nor any manner or fashion of credible scientific thinker. moreover, i have refuted scientifically ad nauseum. i can, will, and do emote as i damn well please as you are well aware. as i recently told another complainant of your inclination, i am who i am and you are not.

 

do you have something on topic to contribute? perhaps something to add to why tsunamis cause water to first recede from a shoreline? no? i thought not.

Guest MacPhee
Posted

i have not been rash. i have read elijah's posts here and in other threads over several weeks and he is no copernicus, nor galileo, nor newton, nor darwin, nor wegener, nor lavoiser, nor darwin nor any manner or fashion of credible scientific thinker. moreover, i have refuted scientifically ad nauseum. i can, will, and do emote as i damn well please as you are well aware. as i recently told another complainant of your inclination, i am who i am and you are not.

 

do you have something on topic to contribute? perhaps something to add to why tsunamis cause water to first recede from a shoreline? no? i thought not.

 

The native American Indian tribes, regarded mad people as inspired by gods. Hence, able to divulge divine wisdom. Reading some posts, I see what they meant.

Posted
... do you have something on topic to contribute? perhaps something to add to why tsunamis cause water to first recede from a shoreline? no? i thought not.

The native American Indian tribes, regarded mad people as inspired by gods. Hence, able to divulge divine wisdom. Reading some posts, I see what they meant.

 

i'll take that as a no.

 

as luck would have it, i am inspired to continue walking my talking and post a resource of acquired scientific wisdom on tsunami and earthquakes.

 

Tsunamis & Earthquakes:

 

About Tsunami and Earthquake Research at the USGS

 

Here you will find general information on how local tsunamis are generated by earthquakes as well as animations, virtual reality models of tsunamis, and summaries of past research studies. The scope of tsunami research within the USGS, however, is broader than the topics covered here. USGS researchers have also provided critical research toward understanding how sediments are transported during tsunami runup and deciphering the geologic record of prehistoric tsunamis. The USGS collaborates closely with the National Center for Tsunami Research.

 

As part of the National Tsunami Hazard Mitigation Program, the USGS has also upgraded the seismograph network and communication functions of the West Coast & Alaska Tsunami Warning Center and Pacific Tsunami Warning Center. This effort is termed CREST -- Consolidated Reporting of EarthquakeS and Tsunamis.

 

Get started!

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...