A Question for people in the Know


#1

First off I am NOT in the maritime industry. That being said, my friend and I are in a heated argument that I think you guys could help me with.

Do you feel an earthquake on a ship?

Neither of us have shipped out or spent more then a week or two at sea so this maybe a REALLY STUPID QUESTION but I would like to prove him wrong.

I say NO

He says YES

Any help?


#2

Sure, there was a tsunami in Denver once…(joke) The only way to “feel” an earthquake would be indirectly as a tsunami. Most energy from submarine earthquakes are dispersed by thousands of miles of ocean and go un-noticed (I watch Discovery)


#3

<strong>Guest:</strong>

Nope, not in a boat, ship airplane or helicopter. You might think you felt one the last time you were aboard anchorman’s workboat but that was just him hitting the pier :wink:


#4

“Nope, not in a boat, ship airplane or helicopter. You might think you felt one the last time you were aboard anchorman’s workboat but that was just him hitting the pier ;)” Nice try. That was your granny’s panties in the starboard wheel.


#5

<strong>“Granny’s panties”? </strong> Are you 11?


#6

Why? Is 11 your cut-off point? Pervert!!


#7

<strong>Guest:</strong>

Tim, I believe your friend is correct, but not a stupid question. In 1985 or 6 I was on an intercoastal voyage from Los Angeles to Corpus Christi and offshore Mexico when I felt a sharp movement, unlike the prevalent sea, which was smooth and swell, which was low and of long wavelength. I looked at the AB and he at me and both said, “What the fuck was that?” There was nothing heard nor seen, just a weird unexpected jolt that did not affect the tug in any other way. Not an hour later, we heard on the AM radio a report of a large submarine earthquake centered at the position we were. Pretty cool.


#8

<strong>Guest:</strong>

No.

Tsunamis? Only those closer to the Indian coast (within 5 miles) felt it… even the fishermen from Tamilnadu who were just 20 miles out did not feel it. For the others, it was like a normal swell.


#9

<p style=“margin-left: 100px; margin-right: 100px;” align="justify]<font face="Bookman Old Style]
The most documented seaquake encounter in modern times occurred on 28
February 1969 when a magnitude 7.8 erupted ~20 kilometers from the position
of a 32,000 ton tanker sailing in ballast from Lisbon to the Persian Gulf.
Ambraseys reports that in the wheelhouse of the Ida Knudsen, compasses and
other permanent instruments, including the radio station binnacles were torn
loose from their mountings and collapsed. Doors and fixtures where broken
from their hinges and mountings. The radar mast was broken. Damage to the
superstructure was more serious amidships than at the aft peak. From
eyewitness accounts it appears that the ship was lifted up bodily, the bow
moving up faster than the bridge, and then the whole ship was slammed back
with violent vibrations, the whole event lasting about 10 seconds. After
hours of drifting helplessly, the ship’s engines were restarted, and with a
bent propeller shaft vibrating horribly, the ship was able to ease back into
Lisbon where it was surveyed and declared a total loss. </font>
<p style=“margin-left: 100px; margin-right: 100px;” align="justify]<font face="Bookman Old Style]
The surveys proved that the hull, machinery and other equipment had
sustained great damage and, because of the permanent deformation and breaks,
the ship had lost a substantial part of her longitudinal strength. The
complete surface of the vessel’s skin from cofferdam to cofferdam buckled in
places with permanent sets of four cm and the hull was twisted 18 cm.
Bulkheads, hull frames and girders were buckled or torn apart and all wing
tanks leaked. The bottom parts of the side platings were torn away from the
girders, by as much as five cm, “effects resembling those of underwater mine
explosions.” </font>


#10

Yes an earthquake can be felt on board a vessel.<br> <br>I was a tug and we had our oil barge on the hip idling off Tacoma in the middle of <span style="FONT-SIZE: 11pt; LINE-HEIGHT: 115%; FONT-FAMILY: ‘Calibri’,‘sans-serif’; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: ‘Times New Roman’; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA]commencement</span> bay, flat calm day when the tug started to viberate, shake and then actually started jumping for about 45 seconds. I watched the 4000lb stick boom on the barge jump right out of it’s cradle. There had been a 5.3 magnitude quake not too far away<br><br>It was pretty weird before that I wouldn’t have thought it possible. I guess when you are close enough to the event the energy is so great that it is transmitted through all the <span style="FONT-SIZE: 11pt; LINE-HEIGHT: 115%; FONT-FAMILY: ‘Calibri’,‘sans-serif’; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: Calibri; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: ‘Times New Roman’; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA]surrounding </span> matter. It may not always produce a tidal type wave but the shock wave can defently be felt and effect vessels at sea.


#11

Hey guys! I don’t no much about the earthquakes thing but I dont think that they are started from submarines! I can say that DOLLY was really rough to ride! It was probabaly the worst storm that I have ever been around! No body should have to ever expereince somethin like that EVER! Sorry that I can’t help you with your earthquake thing but I no what it’s like riding through the eye of a hurricane!


#12

Im no expert on this, but Im deckie on a scientific research vessel, and we have deployed Tsunami warning buoys off the coast of Chile and Thailand, and survey fault lines around the world. If the scientists arent too full of themselves I pick their brain a bit, cuz its pretty interesting work. Anyhow, I think the answer to your question is YES and NO.<br><br>Yes, because a Tsunami (Japanese word for “harbor wave”) is a high frequency shock wave from an earthquake, sometimes over 200 knots per hour! The Tsunami slows as it reaches shallower water, but builds in amplitude. So in a sense, people hundreds of miles away from the epicenter are feeling the EFFECTS of the the earthquake, not the earthquake itself, and I am quite certain people on boats in shallow water are in danger of its damage. <br>Ive had to heave anchor several time because of Tsunami warnings when I was working in the Aleutian Islands. We just sail to deep water until the danger passes. But in deep water, you feel nothing at all. The water compresses and releases so quickly it doesnt move at a frequency slow enough to move a ship or boat. It takes fairly sophisticated doppler sonar to detect this on the warning buoys.<br>But then again, I imagine if you were in 50 feet of water over the epicenter of an earthquake, youd feel something, but 3000 meters? no.<br>I also worked on a seismic vessel, and we would “make earthquakes” by firing powerful air cannons into the water in order to image what lies beneath the sea floor. As we would get near shallow areas the stern of the 270 foot ship would “jump” out of the sea. A shock strong enough to maybe knock over a Bic lighter sitting on a table every minute or so. nothing spectacular, but REAL annoying on a month-long cruise. We would hope to survey a deep area so we could get some sleep at night. <br>Anyhow, To answer your question, The answer is YES and NO.<br>Sort of like the theory of if a butterfly beats its wings in Africa, does it eventually cause a typhoon in Asia?


#13

I am 47 and just got my TWIK and MMD. I am looking for entry level openings in the gulf on crew boats, dive boats, whatever. Anyone know of companies that hire newbis? have sea experience on fishing trawlers in Nova Scotia and Tall ships around the world. ny tip greatly appreciated<br><br>Tom Gibbs