Editing Tide (section)

== Other tides ==
When oscillating tidal currents in the stratified ocean flow over uneven bottom topography, they generate [[internal wave]]s with tidal frequencies. Such waves are called ''[[internal tide]]s''.

Shallow areas in otherwise open water can experience rotary tidal currents, flowing in directions that continually change and thus the flow direction (not the flow) completes a full rotation in {{frac|12|1|2}} hours (for example, the [[Nantucket Shoals]]).<ref name=rocur>{{cite journal |last=Le Lacheur |first=Embert A. |url=https://www.jstor.org/pss/208104 |title=Tidal currents in the open sea: Subsurface tidal currents at Nantucket Shoals Light Vessel |journal=[[Geographical Review]] |date=April 1924 |volume=14 |issue=2 |pages=282–286 |doi=10.2307/208104 |jstor=208104 |bibcode=1924GeoRv..14..282L |access-date=4 February 2012 |archive-date=16 September 2023 |archive-url=https://web.archive.org/web/20230916153559/https://www.jstor.org/stable/208104 |url-status=live }}</ref>

In addition to oceanic tides, large lakes can experience small tides and even planets can experience ''[[atmospheric tide]]s'' and ''[[Earth tide]]s''. These are [[continuum mechanics|continuum mechanical]] phenomena. The first two take place in [[fluid mechanics|fluid]]s. The third affects the Earth's thin [[Solid mechanics|solid]] crust surrounding its semi-liquid interior (with various modifications).

=== Lake tides ===
Large lakes such as [[Lake Superior|Superior]] and [[Lake Erie|Erie]] can experience tides of {{convert|1|to|4|cm|in|abbr=on|sigfig=2}}, but these can be masked by meteorologically induced phenomena such as [[seiche]].<ref>{{cite web |title=Do the Great Lakes have tides? |date=October 1, 2000 |url=http://www.great-lakes.net/teach/chat/answers/100100_tides.html |publisher=Great Lakes Information Network |access-date=2010-02-10 |archive-date=2017-12-30 |archive-url=https://web.archive.org/web/20171230003511/http://www.great-lakes.net/teach/chat/answers/100100_tides.html |url-status=dead}}</ref> The tide in [[Lake Michigan]] is described as {{convert|0.5|to|1.5|in|cm|abbr=on|order=flip}}<ref>{{cite web |last=Calder |first=Vince |title=Tides on Lake Michigan |url=https://wat.lewiscollard.com/archive/www.newton.dep.anl.gov/askasci/phy00/phy00330.htm |publisher=Argonne National Laboratory |access-date=2019-08-14 |archive-date=2019-08-15 |archive-url=https://web.archive.org/web/20190815033734/https://wat.lewiscollard.com/archive/www.newton.dep.anl.gov/askasci/phy00/phy00330.htm |url-status=live }}</ref> or {{convert|1+3/4|in|cm|order=flip|abbr=on}}.<ref>{{cite web |title=moon and Tides |url=http://www.thespaceguy.com/moontides.htm |publisher=Astronomy Briefly |last=Dunkerson |first=Duane |access-date=2010-02-10 |archive-date=2010-01-15 |archive-url=https://web.archive.org/web/20100115000607/http://www.thespaceguy.com/moontides.htm |url-status=live }}</ref> This is so small that other larger effects completely mask any tide, and as such these lakes are considered non-tidal.<ref>{{cite web |title=Do the Great Lakes have tides? |url=http://oceanservice.noaa.gov/facts/gltides.html |website=National Ocean Service |publisher=[[NOAA]] |access-date=2016-04-26 |archive-date=2016-04-23 |archive-url=https://web.archive.org/web/20160423224702/http://oceanservice.noaa.gov/facts/gltides.html |url-status=live }}</ref>

=== Atmospheric tides ===
{{main|Atmospheric tide}}
Atmospheric tides are negligible at ground level and aviation altitudes, masked by [[weather]]'s much more important effects.<!-- and solar thermal tides. However, there is no strict upper limit to the [[Earth's atmosphere]], and the tidal pull increases with the distance from the Earth's center.--> Atmospheric tides are both gravitational and thermal in origin and are the dominant dynamics from about {{convert|80| to |120|km|mi}}, above which the molecular density becomes too low to support fluid behavior.

=== Earth tides ===
{{Main|Earth tide}}
Earth tides or terrestrial tides affect the entire Earth's mass, which acts similarly to a liquid [[gyroscope]] with a very thin crust. The Earth's crust shifts (in/out, east/west, north/south) in response to lunar and solar gravitation, ocean tides, and atmospheric loading. While negligible for most human activities, terrestrial tides' semi-diurnal amplitude can reach about {{convert|55|cm|in}} at the Equator—{{convert|15|cm|in}} due to the Sun—which is important in [[GPS]] calibration and [[VLBI]] measurements. Precise astronomical angular measurements require knowledge of the Earth's rotation rate and [[polar motion]], both of which are influenced by Earth tides. The semi-diurnal ''M''<sub>2</sub> Earth tides are nearly in phase with the Moon with a lag of about two hours.{{Citation needed|date=August 2008}}

=== Galactic tides ===
''[[Galactic tide]]s'' are the tidal forces exerted by galaxies on stars within them and [[Satellite galaxy|satellite galaxies]] orbiting them. The galactic tide's effects on the [[Solar System]]'s [[Oort cloud]] are believed to cause 90 percent of long-period comets.<ref>{{cite journal |title=Periodic variation of Oort Cloud flux and cometary impacts on the Earth and Jupiter
|last1=Nurmi |first1=P. |last2=Valtonen |first2=M.J. |last3=Zheng |first3=J.Q. |name-list-style=amp |journal=[[Monthly Notices of the Royal Astronomical Society]] |volume=327 |issue=4 |pages=1367–1376 |date=2001 |bibcode=2001MNRAS.327.1367N |doi=10.1046/j.1365-8711.2001.04854.x |doi-access=free}}</ref>