In this account of the 1989 Loma Prieta earthquake, the pilot of the Goodyear Blimp gave this account:
Can an earthquake generate atmospheric effects?
Or is his perception some kind of confirmation bias?
Deleted: How did that happen???
I don’t see why not. Air compressions and rarefactions from the quake would most certainly be transferred to the blimp.
How would you distinguish shaking from the earthquake from shaking from turbulence?
You think so? I doubt it. For one thing, not all earthquakes resonate up and down. For two (weird phrase, btw), the force would dissipate way before it got that high up. Or so I conjecture.
The Goodyear blimp doesn’t really fly very high.
I’d think it would take a strong earthquake (which the one referenced in the OP certainly was) but shockwaves can spread through the air as well as the ground, and if they impact an aircraft you’d feel it as a vibration or bump. I don’t see a reason to doubt it offhand, although some solid confirmation wouldn’t hurt, either.
I would expect it depends on which way the ground is shaking.
If the ground is shaking laterally, it would be difficult to transmit those motions, via shearing action, all the way up to a blimp without them being totally dissipated along the way.
If the ground is shaking up and down over a very large area (as in an earthquake, the atmosphere pretty much has nowhere to go *but/i] up and down along with the surface; an aircraft/pilot would experience this a brief an updraft and/or downdraft.
Huh? You don’t think HUGE sound waves would rattle the blimp’s bladder, or whatever it’s called? It’s a huge floating ear drum.
ETA: It’s all the crumbling buildings and exploding transformers too.
I’m guessing that you’d only have to stick a seisograph a few feet above the ground and it won’t read anything. Air isn’t a very good conductor of waves, after all.
Watcha say?
It’s not a good conductor of seismic waves, but it seems to do all right with sound waves, and earthquakes do produce sound.
From The USGS:
We’re not talking about compression/rarefaction of the air so much as large-scale displacement; the frequency of the largest-amplitude quake vibes is single-digit cycles per second, with, amplitudes of several inches or more (PDF file: see page 4). Any aerodynamic particle with a very small time constant - that is, low density and large diameter, such as a near-neutrally-buoyant blimp - will follow such bulk air movements very well.
I guess that was my question; are there HUGE sound waves from an earthquake?
To me, the impact of the air rising at most a few inches would be insignificant when compared to all of the other up/downdrafts that a blimp might experience.
For example, Candlestick Park is about 120ft high, and experiences strong winds from the bay. This wind is going to have to rise to pass over the stadium and I would expect the effect of this rising air to be orders of magnitude stronger that any effect from the earthquake.
I just got back from the doctor’s office where they had a copy of a magazine “California,” which I think was an UC Alumni publication. In one of the side bars was the a question whether you could feel an earthquake from an airplane. The answer was no. Certain earthquakes are capable of creating an “air tsunami” (that’s from article), but by the time it reaches the height of the airplane, it’s too weak to be felt. However, since a blimp flies much lower, then it’s very likely.
Did the article say at what altitude it went from “not likely” to “very likely”? The GYB flies at a typical altitude of 1000 to 1500 feet.
They could be ELF and the bag-of-air might be a good place to be affected by them.
IIRC an earthquake, or any disturbance on a surface between 2 media is going to have 3 different kind of waves.
One, where the motion on the surface is forwards/backwards. One that is left/right. And one that is up/down.
These waves travel at different speeds and have different amplitudes and frequencies. That ground motion IS going to induce air mass motion.
It does not surprise me in the least that a blimp flying low would “feel” something, and that it would also be much more likely to feel it than an airplane for several reasons.
I am not a blimp/earthquake expert…but I do have a degree in physics and have stayed in a Holiday Inn more than once.
The eruption of Krakatoa generated ground movement and a pressure wave that was detected at ground level around the world (actually, it was detected several times as the wave rebounded). Since the Goodyear Blimp flies fairly low, it most likely would have been felt by passengers of the blimp, had it been flying in 1883.
For an excellent read on the subject, see Simon Winchester’s book, *Krakatoa: The Day the World Exploded *.
Seismographs regularly pick up sonic booms from the returning Space Shuttle, as well as other unknown aircraft. Conversely, would an earthquake generate a (sound) wave capable of being detected in the air (in this case a blimp)?
This USGS report offers some info.