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79 Cards in this Set
- Front
- Back
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Why should divers learn about the aquatic realm? |
You'll protect what you undersand and care for;
Help you dive safely |
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What is oceanography?
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The science of recording and describing the ocean's contents and processes
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What is the aquatic realm?
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The study of oceans, lakes, rivers & springs
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What are the four branches of oceanography?
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Biological
Chemical Physical ** Geological |
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What percent of the Earth's surface is covered by water?
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71%
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What is the habitable space on Earth called?
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The Biosphere
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What is the deepest part of the ocean?
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Challenger Deep in the Mariana Trench = 36,000 feet. The average depth of the ocean is 12,238 feet.
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What are the five ocean regions?
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Arctic
Atlantic Indian Pacific Southern |
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What two influences do the oceans produce?
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Weather and world climate patterns;
Resources such as food and O2, and natural resources |
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What is the cycle of water from evaporation to precipitation to runoff called?
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The hydrologic cycle
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Why is the hydrologic cycle relevant?
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If inland water becomes polluted, it makes its way to the ocean. Also, rainfall runoff reduces visibility.
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How do oceans influence climate and weather?
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Oceans act as a global thermostat, dampening swings in temperature
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What temperature does water become densest?
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39.16 degrees
Ice is less dense than liquid water as freezing changes the bond angle between H2 and O, increasing space between molecules |
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Why is it important that ice floats?
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If ice sank, lakes and even oceans would freeze solid, killing all aquatic life
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Why do thermoclines exist?
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Differences in water temperature causes density layers (thermoclines)
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Salinity layers in water are called what?
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Haloclines
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What do currents impact?
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Movement of heat, sediments, nutrients, and organisms within and above the seas
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What causes currents?
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- Influences of surface winds
- Variations in water density - Rotation of the Earth |
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What directions do major currents follow?
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Clockwise in northern hemisphere, counter-clockwise in the southern hemisphere
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How do you dive with a current?
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Swim into the current at the beginning of the dive, and swim near the bottom where current is weaker. Avoid long surface swims.
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What is upwelling?
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An upward vertical current bringing deep water to the surface
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What is downwelling?
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Downward vertical current that push surface water deeper into the ocean
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What nutrient effects do upwelling and downwelling have?
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Upwelling brings nutrients into shallow areas, enhancing productivity. In downwelling nutrients are pushed down, favoring deeper organisms over shallower ones
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A string channel of water flowing away from the shore is called a ________
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Rip current
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How do you identify a rip current?
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A channel of churning choppy water
Areas with notable differences in water color Lines of foam of seaweed moving seawards Breaks in the incoming wave patterns |
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What do you do if diving in a rip current?
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Ride the rip out, move to the side, enter the shore from another spot
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What is the transmission of energy through matter called?
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A wave
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Does water move in wave action?
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Not really. The water itself only rocks back and forth. The energy travels outwards.
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How deep can you feel waves?
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To about half of the wave's wavelength.E.g., if the wavelength is 50', you wouldn't feel it below 25'.
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How do you determine the speed of a wave?
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Speed = Wavelength / Period
So if a wave has wavelength of 50', and a period of 10 seconds, it is moving at 5 feet per second. |
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What causes waves?
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A disturbing force creates waves, restoring forces resist them.
Disturbing forces include wind, changes in gravity, seismic activity, undersea landslides, and volcanoes. |
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What disturbing force is most common?
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Wind
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What are some restoring forces?
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Restoring forces dampen wave action. These include gravity (most important), Earth rotation, and surface tension.
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What is a swell?
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The rise and fall of waves with similar wavelengths and frequencies.
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What is a wave train?
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Groups of swells moving together. As the leading wave loses energy it is picked up by follower waves and eventually dissipates; the energy creates new followers. The train travels at half the speed of individual waves.
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What are deepwater waves?
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Waves in water deeper than half their wavelength. Since no effects are felt below half the wavelength, the bottom plays no part in deepwater waves.
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What are transitional waves?
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Waves in water that is half-wavelength to 20th wavelength in depth. The bottom begins to affect the wave.
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What are shallow-water waves?
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Waves in one twentieth wavelength depth or less. Becomes surf.
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How does wind affect waves?
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Wind Speed: faster winds transfer energy more readily
Wind Duration: Long duration yields larger waves Fetch: Surface area over which energy transfer accumulates |
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How does surf form?
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As waves interact with the bottom, wavelength decreases and height increases. Eventually, the crest moves faster than the trough, and falls over, forming surf.
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What type of wave forms on gentle slope beaches?
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Spilling Breaker: wave top curls over and spills down the wave. Not a major obstacle for divers.
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What are plunging breakers?
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When the wave top flies over the bottom, spilling through the air towards the bottom. More difficult for divers.
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What are surging breakers?
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Walls of water crashing hard on the surface. Occur in very steep beaches. Most difficulty for divers.
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What is wave refraction?
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When waves hit the shore at an angle - the waves refract, or bend, becoming parallel with the shore. Enter at the middle of the cove rather than the sides.
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What happens to waves at headlands (jutting land)?
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Refraction concentrates wave energy on the headland. Enter away from the headland.
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What is wave diffraction?
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When waves pass an obstacle, forming a new pattern.
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What is wave reflection?
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When waves hit a vertical wall and bounce back and forth. Dangerous for divers.
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What can the surf tell you about offshore depth?
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Surf offshore is a shallow area, such as a reef, sand bar or wreck, which may be a good place to dive.
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Besides the gravity of the moon and sun, what else affects tides?
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The imperfect sphere of the Earth
Seasons Time of the month Shape of the ocean basin Rotation of the Earth |
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What tide has a single high and low each day?
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Diurnal Tide
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What tide as two roughly equal high and low tides daily?
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Semidiurnal Tide
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What is it called when there are two unequal tides each day?
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Mixed Tides
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The difference between the high and low tides is called the _______ and is based on ocean basin size and shape
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Tidal Range
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Components of tidal flows:
_______ = Flood current _______ = Ebb Tide _______ = Slack Tide |
_Inflow_ = Flood current
_Outflow_ = Ebb Tide _Midpoint_= Slack Tide |
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How does today flow affect divers?
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Time your entries and exits for slack tides
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Relative strength of tidal influence of the moon vs. sun?
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Mood is twice as strong as sun
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When the moon and sun work together for a tide, what is that called, and what phase of the moon is it?
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"Spring Tide" - when the moon is new, it's on the same side of the Earth as the sun, and they combine. Full moons also have a constructive influence.
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What are neap tides? When does it happen?
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At 1/4 and 3/4 moon phase the moon pulls perpendicular to the sun, moderating the tide
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What causes nearly all injuries involving aquatic life?
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Human carelessness
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How to avoid problems with aquatic animals?
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Treat all animals with respect
Be cautious in low vis - especially where you put your hands Avoid shiny dangly jewelry Remove speared fish immediately Wear gloves and exposure suit to avoid stings and cuts |
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More ways to avoid problems?
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Maintain neutral buoyancy
Move slowly and carefully Watch where you put your hands, feet and knees |
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Before assisting a diver with an aquatic life injury, you should:
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Avoid the same injury yourself
Ask history of the event and location Act quickly Seek medical aid in all cases |
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Factors influencing reactions to venom include:
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Patient size
Body chemistry Current health Location of bite or sting Quantity of venom |
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General signs and symptoms of venomous bites and stings?
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Loss of consciousness, weakness, nausea
Confusion Paralysis Swelling/inflammation Pain or stinging |
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Recommended first aid for venomous marine life?
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Carefully remove foreign matter
Soak in hot water for 30-90 minutes Keep wound below heart treat for shock Apply pressure bandage |
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Result of a box jellyfish sting?
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Severe burning
Skin pain Welts Irrational behavior Respiratory or cardiac arrest |
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Result of a Portuguese man of war sting?
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Pain in lymph nodes in groin and armpits
Muscle pain Nausea Headache Vomiting |
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How to treat of you don't know what stung the patient?
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Assume box jellyfish.
Use forceps to lift off tentacles Do not rinse with fresh water |
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General coral sting treatment?
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Monitor lifeline
Remove stinging material Irrigate with salt water Shave area Ice packs & anesthetic sprays may reduce pain Sitting up OK Activate EMS |
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Treatment of coral cuts?
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Flush with fresh water
If wound stings, rinse with vinegar or isopropyl alcohol Use antibiotics if prescribed Relieve pain with acetaminophen or ibuprofen |
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Treatment of octopus bite and cone shell stings?
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Monitor lifeline
Keep patient still Apply direct pressure Activate EMS |
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Treatment of fish spine injury?
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Monitor lifeline
Activate EMS Keep patient still Immerse in hot water up to 90 minutes If easy, remove spines with forceps Clean wound with soap and water |
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Why dive responsibly?
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Aquatic realm is our playground
Protect and guard the environment they enjoy Reduce long term damage Don't add to the degradation of the aquatic realm |
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How to demonstrate passive interactions?
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Don't approach animals
Move quietly and smoothly |
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How to learn about the aquatic realm?
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Discover Local Diving
Specialties: UW Naturalist, Fish ID, Coral Reef Conservation, AWARE courses |
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When was Project AWARE founded?
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1989 by PADI
1992 a registered non-profit |
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Mission of Project AWARE?
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Dedicated to conserving UW environments through education, advocacy, and action
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Types of Project AWARE activities?
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UW and beach cleanups
Coral reef conservation Shark education & conservation Improved marine protection efforts Environmental training |
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Ten ways to protect the UW environment:
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1 - Dive carefully
2 - Be aware of body and equipment placement 3 - Keep dive skills sharp through continuing ed 4 - Consider how interactions affect aquatic life 5 - understand and respect UW life 6 - be an ecotourist 7 - Respect UW cultural heritage 8 - Report environmental disturbances or destruction 9 - Be a role model for other divers and nondivers in the environment 10 - get involved in local environmental activities and issues |
