Term
| What chemical does pH measure? |
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Definition
| pH measures acidity and basicity of a liquid solution. |
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Term
| Which chemicals are involved in determining pH? |
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Definition
| Hydrogen present in the solution. |
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Term
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Definition
| A substance that has the potential to donate a proton (H+) or accept an electron pair. Has a pH less than 7. |
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Term
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Definition
| A solution composed of an acid and its conjugate base that serves to moderate the pH of the solution. |
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Term
| What is the usual (normal) pH of the ocean? |
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Definition
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Term
| How much has it changed in recent years? |
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Definition
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Term
| Which chemical change in the atmosphere is causing ocean acidification? |
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Definition
| Carbon dioxide in the air is causing ocean acidification. |
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Term
| Describe how a change in chemistry in the atmosphere creates a change of pH in the ocean. Which molecules are involved in the process? |
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Definition
| Carbon Dioxide in the air enters the ocean and becomes carbonic acid. The carbonic acid releases hydrogen, which causes a change in the buffering system and a decrease in the pH levels. |
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Term
How does temperature of the ocean affect this process?
Carbon Dioxide |
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Definition
| Warmer temperature increases the Hydrogen concentration, raising the pH. |
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Term
| Why does it matter if the ocean becomes more acidic? |
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Definition
| Increasing acidity will make it harder for corals to build skeletons and for shellfish to build the shells they need for protection. Corals are particularly important because they provide homes for many other sea creatures. |
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Term
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Definition
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Term
| What are the primary forces influencing currents? |
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Definition
| wind, gravity, and thermal expansion. |
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Term
| What is the Coriolis Effect? |
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Definition
| The Coriolis effect is the apparent curvature of global winds, ocean currents, and anything else that moves freely across the Earth's surface, due to the rotation of the Earth on its axis. |
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Term
| why is the Coriolis effect different in the Northern and Southern Hemispheres? |
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Definition
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Term
| How does the Coriolis Effect help create gyres? |
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Definition
| The gyres form partially because the global mean wind field pushes the surface waters. As the water moves it is affected by the Coriolis force so the resultant flow of the surface waters is between the direction of the Coriolis force and the wind. |
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Term
| What is Ekmann transport? |
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Definition
| is the amount of water affected by surface winds. |
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Term
| Which direction does the Ekman Transport move the water at the surface? |
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Definition
| Right in Northern Hemisphere and Left in the Southern Hemisphere. |
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Term
| How is the direction different than the net effect of Ekmann Transport (from throughout the entire Ekmann Spiral)? |
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Definition
| The Ekman Transport causes the deeper and deeper water to keep turning a bit more and a bit more, causing the Ekman Spiral. Resulting in the water to be about 90 degrees from the wind angle. |
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Term
| How do the wind and Ekmann Transport combine to create up welling? |
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Definition
| Coastal up welling is a result of wind. It can occur when wind blows parallel to the shore or offshore. First, friction caused by wind blowing across the ocean surface creates a current. Next, the Coriolis effect deflects the current to either the right or left (depending upon the hemisphere) and Ekman Transport moves the water mass offshore. |
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Term
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Definition
| pwelling occurs when the surface water is replaced by deeper offshore water. |
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Term
| Why is upwelling important? |
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Definition
| The replacement water, which often contains high levels of nutrients, can result in significant increases in biological productivity, the sea comes alive. |
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Term
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Definition
is a disturbance that
transmits energy from one place to another |
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Term
| How would you describe a wave to someone who had never seen a lake or ocean? |
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Definition
| Movement of water due to a displaced object causing a flow of water. |
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Term
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Definition
. In the open
ocean waves are formed when winds blowing across the
water surface transfer energy to the water. |
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Term
| What is wave interference? |
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Definition
| interactions between waves that meet. |
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Term
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Definition
| A large spontaneous surface wave |
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Term
| How are rogue waves created? |
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Definition
| The primary specifications for a rouge wave are a combination of wind and sea current. When the water current in an area is flowing strongly in one direction, and strong wind currents flow in the opposite direction, the two collide. When they collide, the wind pushes against the water, forcing the water upwards, creating a higher than usual wave. |
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Term
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Definition
| rea of ocean or lake surface over which the wind blows in an essentially constant direction, thus generating waves. |
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Term
| What is the role of fetch in determining how large wave becomes and how fast it moves? |
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Definition
| he longer the fetch length and the faster the wind speed, the larger and stronger the wave will be. |
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Term
| when a wave passes through, what exactly happens to the water? Does the water move forward with the wave? Why or why not? |
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Definition
| As an ocean wave passes, the water moves up and down in a circular pattern and returns to its original position because only the energy is moving forward, not the actual water itself. |
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Term
| How does water depth affect the way a wave behaves? |
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Definition
| If the wave is shallow the depth will determine the speed due to friction with the ground. If its deep than it wont affect the wave. |
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Term
| Describe two differences between a deep-water and a shallow-water type wave. |
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Definition
Deep water waves' speed is affected by the wave length and period.
Shallow water waves's speed is affected by how close to the sea floor they are; due to friction.
Deep water waves occur when the wave travels in water deeper than 1/2 its length |
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Term
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Definition
| A long high sea wave caused by an earthquake or other disturbance. |
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Term
| Describe how earthquakes can cause a tsunami. |
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Definition
| An undersea earthquake pushes against the overlying water, creating a wave with a wave base that reaches the sea floor from the beginning (not just in shallow water). |
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Term
| Besides earthquakes, what else could cause a tsunami? |
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Definition
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Term
| When and where did the two largest tsunami in the last decade occur? |
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Definition
Japan march 20, 2011
Indonesia December 26,2004 |
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Term
| Compared to other tsunamis in the last 100 years, in what way were these two unusual in their size and impact? |
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Definition
| They are the biggest tsunamis with the largest death tolls since 1800s |
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Term
| Why are tsunami shallow-water type waves (even when they start in deep water)? |
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Definition
| because they reach all the way to the sea floor |
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Term
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Definition
| the height onshore, above sea level, that a tsunami reachs. |
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Term
| What is inundation distance? |
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Definition
| the distance inland (from normal shoreline) that the tsunami wave reaches. Depends on the slope and run-up elevation. |
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Term
| Why are tsunami so dangerous and destructive? |
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Definition
-Tsunamis consist of a series of waves. Often the first wave may not be the largest. The danger from a tsunami can last for several hours after the arrival of the first wave, as reflected distance-waves come ashore…
-faster than a person can run
-floating debris does a lot of damage
-looks like low tide
-can occur at any time
-run up can be 20 feet or more |
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Term
| Which coastal areas of the US are most vulnerable to tsunami? Why? |
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Definition
| Northern CA and Oregon are most vulnerable because they get surface currents from Japan --which is susceptible to undersea earthquakes due to the ring of fire. |
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Term
| How many people died in the recent Indian Ocean tsunami? |
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Definition
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Term
| How many people died in the last Japan tsunami? |
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Definition
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Term
| What could explain this difference in number of people dead in the Indian Ocean tsunami vs Japan tsunami? |
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Definition
-Awareness of the signs of a tsunami
-Warning System
-the size and strength of the wave |
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Term
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Definition
U.S.National Tsunami Hazard Mitigation Program (NTHMP)
Detection And Real-Time (DART) reporting of tsunamis in open ocean. |
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Term
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Definition
1) Reduce the loss of life and property in U.S. coastal communities.
2) Eliminate false alarms and the high economic cost of unnecessary evacuations |
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Term
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Definition
| A DART buoy has a pressure sensor on the seafloor recorder that “feels” pressure changes from tsunamis (as small as 1 cm). It also has a surface buoy for real-time communication of the data. The data are relayed via satellite link to NOAA's Tsunami Warning Centers and PMEL. |
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Term
| What happens to a wave as it approaches shore? |
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Definition
| Wave rays bend as they enter shallow water. |
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Term
| Describe the sequence of changes it undergoes. |
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Definition
| The wave rays bend, as they enter shallow water. They drag along the bottom as the wave transitions into a shallow water type. Then develops faster speeds in the waves crest. |
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Term
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Definition
| deviation of the wave from its initial straight-line path because of variations in wave speed |
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Term
| Why does refraction occur? |
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Definition
Sections of the wave front still in deep water continue at original speed
Causes wave crests to refract (bend) |
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Term
| How does refraction affect the way a wave behaves nearshore? |
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Definition
| It results in wave fronts arriving parallel to shore. Also results in points, islands and sand bars receiving more wave energy than bays |
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Term
| Some waves are not just refracted, they are diffracted. What is the difference between these two phenomena? |
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Definition
Diffraction occurs when there is gaps and obstacles the wave must hit.
Diffraction is bending of waves around an obstacle.
Refraction is bending of waves from change in speed. |
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Term
| Why are waves considered to be packets of energy? |
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Definition
| They are short burst of wave action that travels as a unit. |
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Term
| How do we know there is energy in a wave? Can we see it? |
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Definition
| The energy from the sun, transfers to the wind, and then to the waves. It travels as kinetic energy. We can actually see the energy but we can see the energy pushing through the water. |
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Term
| What part of the wave reveals the energy it contains? |
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Definition
| The surface of the wave reveals the energy it contains |
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Term
| Wave refraction and wave energy affect headlands differently compared to bays. Why? |
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Definition
| Because when you add a feature to the shoreline it changes the distribution of wave energy and can enhance deposition or erosion. |
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Term
| Describe how waves reaching these two areas act differently. |
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Definition
| The waves will bend around the obstacle |
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Term
| Which is older: a shore that has lots of points (headlands) and bays or a straight shoreline, with just long, straight beaches. |
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Definition
| Straight shoreline is older |
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Term
| Why would time make any difference to shoreline shape? |
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Definition
| Wave erosion will produce straight shore line over time. |
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Term
| What is longshore drift? Describe which features create this drift. |
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Definition
| Shallow-water waves create currrents as they move water in the direction of the wave path |
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Term
| Name some shoreline features that can be created by longshore drift and describe how. |
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Definition
Longshore currents move sediment (and other ddrops and materials settle out.
This process forms spits and srifting objects) until the current speed andbars (often around sources of abundant sediments, like river mouths and soft cliffs |
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Term
| Beaches change shape after storms. What happens to the sand? Where does it go? |
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Definition
| The waves remove the sediment and move it to the beach up current. |
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Term
| Why are some beaches sandy and some are rocky? How does the presence of a river nearby affect this? |
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Definition
| A beach may be rocky if a headstone is eroding or if the source of the beaches sediment is rocky it will cause the beach to be rocky. If a river is nearby it may be the source. |
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Term
| What forces combine to create tides? |
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Definition
| Gravitational pull of the sun and the moon + rotation of the Earth. |
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Term
| At which latitudes do you expect the highest tides? Why? |
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Definition
| higher latitudes which are more in-sync with the orbit of the moon |
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Term
| Do high tides (or low tides) occur at the same time everywhere? Why or why not? |
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Definition
| The moon controls the tides. The moon orbits the earth, so it is not possible for it to cause the same tidal effects at a given location at the same time each day. |
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Term
| Why is the time of high tide today different than high tide yesterday? By how much is it different? |
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Definition
| The orbit of the moon and the rotation of the earth effect the times. Its off by about an hour |
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Term
| What is the difference between a diurnal and a semidiurnal tide cycle? |
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Definition
Diurnal:
one high and one low tide each day
Semidiurnal:
two high and two low tides each day with equal amplitudes |
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Term
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Definition
| Tidal Bores: wave front formed when high tide surge gets funneled against a outflowing river current |
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Term
| What is a standing wave? How is one created in the oceans ? |
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Definition
Seiche = standing wave.
Can be created by reflected progressive waves |
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Term
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Definition
| an internal standing wave (between layers of water) |
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Term
| Why do seiches most often form on a thermocline or picnocline? |
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Definition
| called internal waves. the area is unstable so it often causes seiches. |
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Term
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Definition
|
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Term
| What effect do seiches have on the surface water? |
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Definition
| surface water oscillates by sloshing between opposing shores within the lake basin, decreasing in height with each rocking back and forth until it reaches equilibrium. |
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Term
| Global warming is causing the ocean sea level to rise, partly because of glacier ice melting but also because warm water takes up more space than cold water (an effect called thermal expansion). What affect is this likely to have on the shorelines of New England? The shorelines of the low elevation coastal states (like Florida, Alabama, Lousiana, Mississippi)? |
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Definition
New England shorelines are looking to experience coastal flooding and shoreline erosion. Cape Cod is one of the more vulnerable areas.
Areas of lower elevation will experience retreating and eroding shorelines. |
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Term
| Beach erosion is affecting millions of acres of shoreline around the world. From what you’ve learned in this class, what is likely to have the greatest long-term success at reducing erosion land losses: building sea walls, preventing development near shore, regulating CO2 releases to the atmosphere. |
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Definition
| Our best bet is to regulate CO2 in the air. Preventing development near shore would do nothing for the coast other than save houses from being flooded and creating a sea wall wouldn't save our beautiful beaches either. |
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Term
| If global warming causes thermoclines to develop at shallower depths in the ocean, would you expect to see more seiches develop? Why or why not? |
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Definition
| You may see more and bigger because of the unstable layer of the ocean oscillating. |
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