Term
| How much of the earth's surface is covered by water? |
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Definition
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Term
| How much of the water that covers the earth is ocean? |
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Definition
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Term
| What is the average depth of the ocean? |
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Definition
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Term
| How do you find the longitude of a given point? |
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Definition
| It is the time difference from the prime meridian times 15 degrees (because the earth rotates 15 degrees/hour) |
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Term
| How do you find the latitude of a given point? |
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Definition
| It is the angular distance measured North or South |
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Term
| Who created the first ocean bathymetric map and when? |
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Definition
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Term
| How much water is there? (volume) |
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Definition
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Term
| What is the percentage breakdown of the water on earth? |
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Definition
| 97% in oceans, 2.1% in ice, 0.6% in groundwater supplies, 0.01% in lakes and rivers, 0.001 in atmosphere. |
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Term
| Why can't meteors be sources of extraterrestrial delivery? |
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Definition
| The levels of Xenon in our atmosphere are very low, and there's much more Xenon in meteors. It's a noble- nonreactive- gas, so there's not really anywhere it could have gone. |
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Term
| What is the issue with comets? |
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Definition
| The D/H ratio of most comets is twice as high as the ratio in ocean water, except for the D/H ratio of comet linear, which is similar to ocean water. |
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Term
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Definition
| mean shape of the earth. topographic profile of planet above and under water. |
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Term
| What is the average elevation above sea level? |
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Definition
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Term
| What is the average elevation below sea level? |
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Definition
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Term
| Properties/density of continental crust |
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Definition
-granatic
-derived from partial melting of oceanic crust
-Rich in Si, K, light color
-Average density= 2.7 g/cc |
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Term
| Properties/density of oceanic crust |
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Definition
-Basaltic
-derived from partial melting of the mantle
-Rich in Fe, Mg, dark color
-Average density= 3.0 g/cc |
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Term
| Why do we have different types of rock? |
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Definition
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Term
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Definition
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Term
| Average thickness of continental crust? Oceanic crust? |
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Definition
Continental=avg thickness is 40km, max is 70km
Oceanic= 5km, max is 10km (rides lower on mantle) |
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Term
| Who proposed continental drift, and when? |
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Definition
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Term
| What are the layers of the earth? |
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Definition
| -layers of the earth: lithosphere (crust and upper mantle), asthenosphere mantle), mesosphere (mantle), outer core (core), inner core (core). |
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Term
| Where does most volcanism occur? |
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Definition
| 80% occurs at spreading centers |
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Term
| How do slow spreading and fast spreading differ? |
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Definition
-slow spreading: high, rugged, narrow, peaked ridges, oceans deeper. ex: mid-atlantic ridge.
fast spreading: lower, broader, gentle ridge, oceans are shallower. ex: east pacific rise-type. |
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Term
| How deep is the Marianas Trench? |
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Definition
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Term
| Where does sunlight reach in the ocean? |
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Definition
| sunlit water= <200m, twilight= 200=1000 m, fully dark > 1000 m |
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Term
| What are the zones of the ocean? |
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Definition
| bathyl zone: 200-2000m, abyssal zone: 2000-6000m, hadal zone >6000m. |
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Term
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Definition
| -sediment types: terrigenous (most sediment is this kind/thickest near continents), biogenic, chemical, volcanogenic, cosmogenic. sedimentation patterns affected by tectonics (active and passive margins). |
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Term
| Examples of biogenic sediment |
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Definition
| -diatoms (photosynthetic) and radiolaria (non-photosynthetic): SiO2, cocolithophorids (photosynthetic) and foraminifera (non-photosyntetic): CaCO3. |
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Term
| Examples of chemical sediment |
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Definition
| evaporites, manganese nodules |
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Term
| Where is sediment located? |
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Definition
| -continental margins take up 78% of ocean sediment while the deep-sea takes up 22% of ocean sediment. |
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Term
| What are the rates of sedimentation? |
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Definition
| Margins build up to 5 cm of sediment a year, deep sea= 1-10 mm/year |
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Term
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Definition
| 4.5 km (deeper if there is warm water, lower pH, or lower pressure) |
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Term
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Definition
| -angle at which H's bond to O is 105°. density of O atoms is 10 times that of H. Hydrogen bond strength is 4% of covalent bond strength. |
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Term
| What is the percent of dissolved constituents in ocean water? What is the average salinity? |
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Definition
| -dissolved constituents range from 33‰-38‰. avg ocean salinity is 35‰ (ranges from 33-38%) |
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Term
| What is energy that breaks bonds? |
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Definition
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Term
| What is energy raises temperature? |
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Definition
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Term
| How much energy is generated by evaporation from the ocean? |
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Definition
| 23 billion megawatts of energy (360,000 km^3) |
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Term
| What is the difference between velocity in dry air and in water? |
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Definition
Dry air: 334 m/sec
Water: 1450m/sec |
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Term
| How deep is the SOFAR channel? |
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Definition
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Term
| What is sound travel time? |
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Definition
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Term
| How far from the source can sound in the SOFAR channel be detected? |
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Definition
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Term
| How much of radiation from the sun is visible light? |
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Definition
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Term
| how many m/sec does sound travel in water? |
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Definition
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Term
| What types of light exist in the ocean? |
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Definition
| gamma ray, xray, ultra-violet, visible, infared, microwave, radio |
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Term
| What wavelengths are absorbed by water first? Transmitted deeper? |
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Definition
| Longer wavelengths absorbed first and shorter wavelengths transmitted deeper |
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Term
| How much light is transmitted to different depths? (in percentages) |
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Definition
| Amount of light: 1 m= 45%, 10 m= 16%, 1000 m= 1% |
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Term
| What did Fridtjof Nancen do? |
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Definition
| froze his ship, noticed that iceberg drift is 20-40 degrees right of wind direction |
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Term
| Where does motion end up in Eckman transport? |
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Definition
| Motion ends up 180 degrees from surface, 225 degrees from wind direction, and retains 4% of surface water speed (which is 1.5-2.5% of wind speed) |
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Term
| What is net Eckman water transport? |
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Definition
| Net water transport is 90 degrees to right (n hemisphere), 90 left in Southern |
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Term
| How deep is the Eckman layer? |
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Definition
| Eckman layer is 100-200 m MAX depth (1-2 % of ocean depth) |
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Term
| What is the effect of stronger winds on Eckman transport? |
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Definition
| Stronger winds=less deflection=lower latitudes=deeper Eckman layer |
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Term
| Is there Eckman transport at the Equator? |
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Definition
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Term
| At what rate does NADW form? |
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Definition
| 15 million m^3 per second |
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Term
| What are the layers of ocean water? |
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Definition
| (from top down) Antarctic intermediate water, North atlantic deep water, Antarctic bottom water |
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Term
| How fast are wind speeds in hurricanes? |
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Definition
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Term
| What is the sea surface temperature necessary for a hurricane? |
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Definition
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Term
| Minimum distance from Equator required for a hurricane? |
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Definition
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Term
| What direction do hurricanes in the N hemisphere rotate? |
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Definition
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Term
| for every 1 millibar drop in pressure, how much does the sea surface rise? |
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Definition
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Term
| What is the major factor in a storm surge? |
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Definition
| 85% of surge due to winds |
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Term
| What is the scale of measuring hurricane strength called? |
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Definition
| The Saffir-Simpson scale. |
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Term
| How much energy is generated during a hurricane? |
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Definition
| Energy from hurricane up to 200 times the world wide electrical generating capacity or 6 months of US energy consumption |
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Term
| What is the amplitude of a wave? |
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Definition
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Term
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Definition
| (t)= time for one wavelength to pass a fixed point |
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Term
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Definition
| (F)= # of wave crests/unit t passing a point (or 1/t) |
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Term
| What is the definition of wave base? |
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Definition
| height at depth ½, orbital diam- 4% of height |
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Term
| Deep vs. intermediate vs. shallow water waves |
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Definition
Deep water waves= depth is greater than wavelength/2
intermediate= depth is less than wavelength/3
Shallow water= depth is less than wavelength/20 |
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Term
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Definition
| Cusp angle is less than 120 degrees (crowded waves cusp), h/wavelength is greater than 1/8 |
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Term
| How do you find the celerity of deep water waves? |
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Definition
1.25(square root of lamda)= lamda/t
Answer in m/sec |
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Term
| How do you find the celerity of shallow-water waves? |
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Definition
| 3.1(square root of the depth)- must be in meters |
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Term
| How large is the pycnocline? |
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Definition
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Term
| How large are internal waves? |
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Definition
| can be greater than 1000 m and wavelengths from 100s to 1000s of meters with long periods |
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Term
| What percentage of waves are 1 m, 1-4 m, and 4-6 m? |
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Definition
| 40% of ocean waves are less than 1 m high, 40% are 1-4 m, 10% are 4-6 m |
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Term
| Definition of significant wave height? |
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Definition
| 40% of ocean waves are less than 1 m high, 40% are 1-4 m, 10% are 4-6 m |
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Term
| What is the Significant Wave Height? (SWH) |
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Definition
| average of largest 33% of waves for a given set of conditions |
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Term
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Definition
| greater than twice SWH; very rare (less than 1: 300,000) |
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Term
| How much force is exerted by a 30 m wave? |
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Definition
100 tons/m^2
(30 tons/m2 force needed to dent the hull of a ship) |
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Term
| What's the difference between a bay and a headland? |
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Definition
| headlands= sites of erosion, bays=sites of deposition |
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Term
| How densely populated are coastal cities? |
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Definition
Greater than 50% of the pop. Lives within 50 miles of the coast
23/25 most densely pop. cities are coastal |
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Term
| What percentage of the coast is eroding? |
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Definition
| 13% of coastline critically eroding, 74% eroding, 13% stable or aggrading |
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Term
| How has the icecap volume changed over time? |
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Definition
| 18,000 y.b.p= 120 m (400 ft) lower than now |
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Term
| Rates of current sea level rise |
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Definition
Sea level rise- 8 cm/degree C
Sea level rise from 1900-2000= 1.7 plus or minus .5 mm/year
Current rate of sea level rise near us is 1-3 mm/year |
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Term
| how many high/low tides are there each day, and how long do they last? |
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Definition
| There are two of each per day and they last for about 50 minutes |
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Term
| How does the solar tide generating effect compare to the lunar tide generating effect? |
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Definition
| Solar tide generating effect= 46% of lunar effect |
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Term
| How do the solar and lunar bulges compare? |
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Definition
| Solar bulge is half as big as lunar bulge |
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Term
| How many spring tides and neap tides are there per month? |
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Definition
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Term
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Definition
Perigee (moon)= av. 357, 500 km,
Apogee (moon)= av. 407,500 km |
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Term
| What is Aphelion? Periphelion? |
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Definition
Aphelion(sun)= 1.02 a.u away
Periphelion (sun)= .98 a.u away |
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Term
| How often do maximum possible astronomical spring tides occur? |
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Definition
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Term
| What is the angle between the equator and the moon? |
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Definition
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Term
| What is the wavelength of a tide? |
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Definition
| Earth’s circumference= 40,000 km, tide wavelength= 20,000 km |
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Term
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Definition
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Term
| Are tides shallow water or deep water waves? |
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Definition
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Term
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Definition
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Term
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Definition
| Places of equal high tides |
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Term
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Definition
| Places that have high tides at the same time |
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Term
| When was the invasion of Tarawa? |
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Definition
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Term
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Definition
| Epipelagic zone= surface to 200m, mesopelagic zone= 200-1000 m, Bathypelagic Zone= 1000-2000, Abyssopelagic zone= 2000-6000 |
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Term
| Formulaic example of photosynthesis |
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Definition
| H20 + CO2 + light = CH20 +02 |
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Term
| Formulaic example of chemosynthis: |
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Definition
| CO2 +02 + 4H2S = CH2) +4S + 3H2O |
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Term
| At what depth is the photosynthetic peak? |
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Definition
| 1-3 meters below the surface |
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Term
| How much Carbon can be found in different places in the ocean? |
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Definition
Center of gyres: .1 gC/m2/day
Coastal oceans: 1 gC/m2/day
Coastal upwelling zones: 2 g C/m2/day |
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Term
| Time from high tide to low tide? |
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Definition
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Term
| By how many minutes are tides delayed each day? |
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Definition
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Term
| What factors modify tides? |
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Definition
Ocean depth, continents dividing the ocean basins, coastline shape
--> "Dynamic theory of tides." |
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Term
| What is the equilibrium theory of tides? |
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Definition
| The gravitational effects of our solar system neighbors, the moon and the sun, cause tides. |
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Term
| Primary/secondary effects of the equilibrium theory of tides |
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Definition
Primary: lunar, solar
Secondary: distance from moon, distance from sun, earth's axis tilt |
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Term
| In the earth-moon system, what is the common center of mass called? |
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Definition
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Term
| How long is the tidal day and why? |
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Definition
24 hours and 50 minutes
In 1 Earth day, moon travels through 12° of arc
The tide bulge follows the moon
Earth must rotate 12° (= 50 minutes) to catch up |
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Term
| What is the speed of the tide? |
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Definition
| If using equilibrium theory of tides, it would be 1600 km/hour. But because of modifications of dynamic theory (waves feel the bottom), the actual speed is 3.1 times the square root of the depth (3800 m) makes it more like 700 km/hour |
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Term
| What causes amphidromic circulation? |
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Definition
| effect of continents + coriolis effect |
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Term
| What direction is the amphidromic system in the Northern hemisphere? |
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Definition
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