Tides Flashcards
(41 cards)
What is the tidal range?
The tidal range is the difference in height between high tide and low tide.
What are tidal currents?
horizontal movement of water that often accompanies incoming (flood) and outgoing (ebb) tides.
What are slack currents?
weakest currents, occur during flood and ebb tides.
How does the moon affect tides?
The moon’s gravitational attraction, along with the sun’s, generates tides through mutual gravitational forces.
What is Newton’s law of universal gravitation?
Newton’s law states that the force of gravity between two objects is proportional to their masses and inversely proportional to the square of the distance between them.
What is the approximate distance from the Earth to the Moon?
The distance from the Earth to the Moon is approximately 380,000 kilometers.
What is a spring tide?
A spring tide occurs when the Earth, Moon, and Sun are aligned, resulting in the highest high tides and lowest low tides.
What is a neap tide?
A neap tide occurs when the Earth, Moon, and Sun are at right angles to each other, resulting in the lowest high tides and highest low tides.
How often does the spring-neap cycle occur?
lasts approximately 13.66 days, or around two weeks.
What causes inequalities in spring tides?
changing distance between Earth and Moon, as well as the Moon’s elliptical orbit.
What is the lunar day duration?
A lunar day, or tidal day, is approximately 24.84 hours.
What are the assumptions of an equilibrium tide?
no presence of continents, instantaneous water inertia response, and influence of friction and Coriolis effect.
What are the characteristics of dynamic tides?
Dynamic tides are complex and account for factors like ocean basins and coastlines, unlike the hypothetical equilibrium tide.
What are Kelvin waves?
propagate along shoreline and influenced by the Earth’s rotation.
What is an amphidromic point?
a location where tidal movement is minimal, and it rotates around it.
How are co-tidal lines useful in tide charts?
indicate time passage of high tide at various locations.
What is a key feature of narrow basins regarding tides?
Narrow basins can develop true amphidromic systems that resonate with tidal forcing frequencies.
What are tidal constituents?
known components that describe precise frequencies of tides.
How do biological rhythms relate to tides?
Many organisms, such as crabs and snails, are attuned to the tidal cycle, influencing their biological rhythms and reproductive processes.
What is the significance of spring tides for marine invertebrates?
Spring tides are crucial for reproductive processes in marine invertebrates.
What influences the strength of tidal currents?
The strength of tidal currents is influenced by local geography.
How do high latitudes differ in tidal patterns?
High latitudes typically experience diurnal tides.
What are mixed tides?
occur in mid-latitude regions, show characteristics of both diurnal and semidiurnal tides.
How does Earth’s rotation impact tidal bulges?
Earth’s rotation causes tidal bulges to be inclined with respect to the equator.
