What is the smallest body of water in which tides can be detected?
What is the smallest body of water in which tides can be detected? (continued)
Eric Kvaalen Les Essarts-le-Roi, France
The Sea of Japan has almost no tides, but I guess they are still detectable. This sea does not have a period of natural oscillation linked to a lunar or solar period, and is quite cut off from the ocean, which is why the tides are low.
Stephen rowe Shepperton, Middlesex, United Kingdom
Early in my career I worked in the ships division of the National Physical Laboratory in the UK. Facilities included a huge indoor tow tank (sadly long demolished to make way for a supermarket). This reservoir was 400 meters long, nearly 8 meters deep and contained more than 45 million liters of water.
Model ships and other marine vehicles were towed into the tank by a motorized cart at precise speeds, so that resistance and propulsive efficiency could be measured to help refine the hull design. and propellers.
There was great interest in any disturbance of the supposedly static water, as this could introduce errors in the measurements, so the water level fluctuations and currents were carefully measured.
The main components of these disturbances were residual currents, which could persist for days after towing a large model. However, I remember that a semi-diurnal slosh, or cuttlefish, due to the tides could also be clearly seen in the reservoir data.
Garry Trethewey Cherryville, South Australia
It depends on the sensitivity of the detector and the absence of confounding factors like the wind blowing on the water.
Any body of water, even in a cup or thimble, will respond to gravity and therefore be influenced by the moon. Detection then depends on how much you are willing to spend on sophisticated equipment.
To answer this question – or ask a new one – email [email protected]
The questions should be scientific inquiries into everyday phenomena, and the questions and answers should be concise. We reserve the right to modify materials for clarity and style. Please include a mailing address, daytime phone number, and email address.
New Scientist Ltd retains full editorial control over published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.
You can also send your responses by post to: The Last Word, New Scientist, 25 Bedford Street, London WC2E 9ES.
Baths and conditions of application.