OCNG 251Exam # 3 Study Guide Summary of EmailsInvasion of Lionfish: Lionfish have increased, eating other reef fish and mollusks and attacking commercially important species like grouper and snapperIdeas so far to reduce the amount of Lionfish1. Hunt them2. Eat them3. Train sharks to eat them4. Stop importing5. IPhone AppPartial Eclipse:The Moon will passed in front of the Sun on October 23 and what we saw was a partial solar eclipse…but remember never look at the sun without proper filters Megalodon:Scientists now have a better theory on how megalodon, a giant 60 ft shark, went extinct;they estimated it to be about 2.6 million years agoCh. 8 (Waves): I. Wave nomenclature – wavelength, period, height, steepness, frequency, speed- Wavelength: The distance from any point on a wave to an identical point on the next wave. Trough to Trough. Crest to Crest. etc. - Period: The time between two successive waves- Height: The vertical distance between crest and trough is the wave- Steepness: The ratio of wave height (H) to wavelength (L)- Frequency: The number of waves produced in a given amount of time- Speed: The rate of which a wave travels. Wavelength divided by periodII. Wave types – capillary, gravity, wind, tsunami, internal, standing- Capillary Wave: waves have wavelengths less than about1.74 cm (0.7 in) and surface tension is the major restoring (“flattening”) force.o -Sailors call these “catspaws”- Gravity Wave: waves have wavelengths more than about1.74 cm (0.7 in) and gravity controls wave propagation and restoration- Wind Wave: Capillary and gravity waves are wind driven- Tsunami Wave: Caused by seafloor earthquakes; Referred to in popular press as “tidal” waves, but tsunami have nothing to do with tides- Internal Wave: Density interfaces occur within the ocean, and not just at the air-sea interface; internal waves can reach heights of 100 m (330 ft)- Standing Wave: Standing waves are the result of two waves of the same length moving in opposite direction; Happens in closed basins when waves reflect off basin walls (e.g. “bathtub slosh”)III. Characteristics of waves in deep water and shallow water: speed, particle motions- Deep Water: Water depth (d) is greater than one-half of the wavelength; are not affected by (they don’t “feel”) the ocean bottom; speed depends only on the wavelength- Shallow Water: Depth of the water is less than 1/20 of the wavelength; are influenced by the water depth (and they do “feel” the bottom)VI. Wind-generated waves: sea, swell, surf and breakers- Sea: A portion of the ocean where waves are being generated by wind.- Swell: A free ocean wave by which energy put into oceanwaves by wind in the sea is transported with little energy loss across great stretches of ocean to themargins of continents where the energy is released in the surf zone- Surf zone: The near shore zone of breaking waves- Breaking: Waves that break in the surf zone because particle motion near the bottom of the wave is severely restricted, slowing the waveformV. Factors determining the growth of wind waves: wind speed, duration and fetch- Wind Speed- Duration: The length of time which the wind blows in one direction- Fetch: The distance over which the wind blows in one directionVI. Concept of a fully-developed sea- A fully-developed sea is found when waves do not continue to grow (i.e. the waves lose energy at the same rate as energy is supplied by the wind)VII. Interference patterns and “rogue” waves- Interference patterns: The overlapping of different wave groups, either in phase (constructive interference, which results in larger waves), out of phase (destructive interference, which results in smaller waves), or some combination of the two (mixed interference)- Rogue Waves: Rogue waves are waves that can reach 30m or more in height; Thought to occur from constructive wave interference (e.g. “Perfect Storm”); Especially dangerous in areas where large wind waves encounter strong currents (e.g. Agulhas Current or theGulf Stream)VIII. Refraction and reflection of waves- Refraction: Waves typically do not approach beach at a perfect right (90°) angle; Part of wave that feels bottom first will slow down; Waves bend towards shallow water- Reflection: In a system with walls, can form standing waves. Wavesneed correct wavelength/ frequency- In harbors, these "resonances" are known as seiches- Standing waves and the “bathtub slosh”- Standing Waves: The sum of two waves with the two waves with the same wavelength moving in opposite directions, resulting in nonet movement- Bathtub Slosh: Happens in closed basins when waves reflect off basin walls (e.g. "bathtub slosh" a.k.a seiche)IX. Tsunami, storm surges and internal waves- Tsunami: A seismic sea wave. A long-period gravity wave generated by a submarine earthquake or volcanic event- Storm Surges: When long, fast waves surge ashore they can do a lot of damage- Internal Waves: A wave that develops below the surface of a fluid, the density of which changes with increased depthCh. 9 (Tides):I. Orbital mechanics: Newton’s gravitation and centripetal force- Every object in space is attracted to every other object by a force called gravity- Objects in motion follow a straight-line path unless acted on by an unbalanced force- Centripetal force is the inward pull you exert on the string to keep the ball moving in a circular pathII. The tide-generating force and the “tidal egg” The tide-generating force: the difference between the- gravitational attraction and the- °centripetal force acting on the water in the oceanIII. Semidiurnal, diurnal and mixed tides- Semidiurnal: Tide with 2 high and low points each tidal day- Diurnal: Tide with one high and low point each tidal day- Mixed Tides: Tide system where high tides regularly reach different heights and low tides regularly drop to different levelsIV. Relative influence of the Moon and the Sun- The gravity of both the sun and the moon that cause ocean tides onEarth. The moon's gravity is the most influential because it's much closer to Earth than the sunV. Consequence of lunar declination – diurnal inequality- Lunar Declination causes the Diurnal Inequality- Unequal highs and lows result- Declination angle (max = 28.5 deg)VI. The lunar day: why it is longer than the solar day?- The lunar day is 50 minutes longer than a solar day because the moon revolves around the Earth in the same direction that the Earth rotates around its axis. So, it takes