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Video & photos of people exploring exposed sea bottom are making me twitch. Not tsunami, but tides & storm surges will rise deadly-fast.
Q: Why is ocean floor exposed?
A: Wind is pushing water away (drawback); it'll rise rapidly with storm surge soon.
A: Wind is pushing water away (drawback); it'll rise rapidly with storm surge soon.
Q: Surely they can run to safety!
A: Seafloor is flat. Florida is flat. Surge is several meters. That's a long run.
A: Seafloor is flat. Florida is flat. Surge is several meters. That's a long run.
Complications:
1. Curiosity-crowds & damaged infrastructure hamper speedy retreats.
2. Humans chronically overestimate own capabilities.
1. Curiosity-crowds & damaged infrastructure hamper speedy retreats.
2. Humans chronically overestimate own capabilities.
Q: Just like a tsunami!
A: Kinda. Storm surge is bulge (not wave series) so wind waves are on a higher water base.
A: Kinda. Storm surge is bulge (not wave series) so wind waves are on a higher water base.
Sigh. Wrong (but topical) link. Correction one on storm surge are these mobile-unfriendly animations here: nhc.noaa.gov/surge/ 
Storm surge arrival is coinciding with high tide for bonus impending terribleness (storm tide):
Q: Pfft, 10-15 vertical feet isn't that far!
A: Those huge stretches of exposed ocean floor? That's -3.5 feet.
A: Those huge stretches of exposed ocean floor? That's -3.5 feet.
Q: How fast is the storm surge coming in?
A: Water level (red line) is climbing at feet per minute.
A: Water level (red line) is climbing at feet per minute.
If you were out exploring sea floor, you'd be already doomed by the time you saw water & realized something was wrong. I hope everyone fled.
Q: What's the difference between storm surge & tsunami?
A: Formation, mechanism, behaviour, impact, models... almost everything but material
A: Formation, mechanism, behaviour, impact, models... almost everything but material
Storm surge is bulge piled up by low pressure (suction!) & wind.
Tsunami are waves triggered by a disruption (quake, impact, landslide...).
Tsunami are waves triggered by a disruption (quake, impact, landslide...).
Storm surges elevate water levels as a sudden-onset flood. Water stays.
Tsunami flood-retreat-flood-retreat between wave crests & troughs.
Tsunami flood-retreat-flood-retreat between wave crests & troughs.
When storm surge hits max, wind waves soak a little higher but that's it.
For tsunami, later crests may be higher than crest of first wave.
For tsunami, later crests may be higher than crest of first wave.
Both are water with complex local interactions on shorelines, but modeled very differently in SLOSH (surges) & MOST (tsunami).
Wavelength & amplitude allow us to compare scale. How big is a single wave?
(Tiny lies: Storm surge can only kinda be approximated as wave)
(Tiny lies: Storm surge can only kinda be approximated as wave)
Rough maximum wavelengths:
(Normal) wind wave: 10s of m
Storm surge*: 10s of km
Tsunami: 100s of km
Tides: 10,000s of km
* "wavelength"ish
(Normal) wind wave: 10s of m
Storm surge*: 10s of km
Tsunami: 100s of km
Tides: 10,000s of km
* "wavelength"ish
Both tsunami & storm surge can kill people through rapidly-rising water & subsequent problems. Both are nasty. But one isn't subset of other
Thankfully, response is the same for both: Heed warnings (official or natural). Head to high round or vertical refuge. Stay there.
