Clemson Geology 1010 - Exam 3
What does precession affect? - Correct Answer-- time of year *(WHEN)* you experience
each season
True or False: The Milankovitch cycles can synchronize to balance or cancel. - Correct
Answer-True.
- note: cycles have different time scales
How does the atmosphere control climate? - Correct Answer-- Albedo
Albedo - Correct Answer-- measure of reflectivity, how much energy is going to be lost
- in atmosphere
-cloud are very reflective (20% reflected)
What does energy react with to result in a loss of insolation? - Correct Answer-- w/
gasses
- clouds
- ground surface
**this totals to a loss of 30% of insolation**
What influences climate? - Correct Answer-- oceans, plate tectonics, biosphere
*not just atmosphere*
System Interactions - Correct Answer-- interactions among all climate-influencing
components are complicated to untangle
Feedbacks - Correct Answer-- interactions where one component changing causes
other changes, then original component changes again
Positive Feedback - Correct Answer-- every time cycle is completed, cycle is repeated
ex: when A increases, B changes, A increases again (temp incr, ice melts, temp incr
more)
*doesn't always have to be increase
(temp decr, ice forms, temp decr more)
**hard to break out of cycle**
Negative Feedback - Correct Answer-- when cycle is completed, next time through
cycle, opposite result occurs
ex:
1-when A incr, B decr
2-when B decr, A decr
,(next time through)
3-A decr, B incr
4-B incr, A incr
(back to step one)
**creates a stabilizing see-saw effect**
(neither A or B gets too high/low)
What controls climate? - Correct Answer-- energy/heat is needed to change climate
Insolation - Correct Answer-- energy from the sun that reaches the earth
* "incoming" + "solar" + "radiation" *
- several things affect how much insolation the earth receives
Aphelion - Correct Answer-- variation in insolation
- max distance earth is from the sun
* 152 million km from the sun *
Perihelion - Correct Answer-- variation in insolation
- min distance earth is from the sun
* 147 million km from the sun
Milankovitch Cycles - Correct Answer-- cause variation in insolation
- 3 cycles:
1. Eccentricity
2. Obliquity (tilt)
3. Precession
Geology in the News - Correct Answer--oldest confirmed animal fossil identified
-Dickinsonia
-558 MA --> 15-20 million years before the Cambrian Explosion
-Fossils have been found for decades, but difficult to identify
Why do we care about the climate? - Correct Answer-- climate is influenced by many
parts of the earth
-we deal with climate everyday
-we don't have another planet
Climate - Correct Answer-- average surface conditions on Earth over LONG time scales
(decade minimum)
Weather - Correct Answer-- average surface conditions on Earth over SHORT time
scales
(hours, days, weeks)
, Climate on earth is... - Correct Answer-- complicated, not simple
- varies in different parts of the earth
Eccentricity - Correct Answer-- Milankovitch cycle
- looks at shapes of earths orbit
- switches back and forth from eccentricity min and max ~ every 50,000 years
***BIG IMPACT ON ICE AGE***
- cycle is 100,000 years
Eccentricity Maximum - Correct Answer-- ellipse shape
Eccentricity Minimum - Correct Answer-- circular shape/pattern
Obliquity (tilt) - Correct Answer-- Milankovitch cycle
- tilt of earth on its axis
- "rocks" back and forth by 2 degrees
- cycle is ca 41k years (takes ~ 20k yrs to "rock back") *(where season are on planet)*
How much does the obliquity angle change? - Correct Answer-- ~ 2 degrees
- think of rocking chair
How much does the obliquity angle change the insolation? - Correct Answer--
significantly
- reason why we have opposite seasons in N and S hemispheres
Seasonal Contrast - Correct Answer-- how different summer vs winter temperatures are
High Obliquity Angle - Correct Answer-- completely "rocked" back
- high seasonal contrast
Low Obliquity Angle - Correct Answer-- low seasonal contrast
Precession - Correct Answer-- Milankovitch cycle
- 3-D "wobbling" motion, tilted earth rotating around straight, vertical line (creates circle)
- takes ~ 11k years to get 1/2 way through cycle (1/2 way is when seasons flip months,
full cycle ~ 22k yrs)
How does Atmospheric Gas control climate? - Correct Answer-- atmo-composition
gasses
- greenhouse effect
Atmo-Composition gasses - Correct Answer-- Nitrogen, 78%
- Oxygen, 21%
- rest is greenhouse gasses: can get insolation close to surface and traps some of it
What does precession affect? - Correct Answer-- time of year *(WHEN)* you experience
each season
True or False: The Milankovitch cycles can synchronize to balance or cancel. - Correct
Answer-True.
- note: cycles have different time scales
How does the atmosphere control climate? - Correct Answer-- Albedo
Albedo - Correct Answer-- measure of reflectivity, how much energy is going to be lost
- in atmosphere
-cloud are very reflective (20% reflected)
What does energy react with to result in a loss of insolation? - Correct Answer-- w/
gasses
- clouds
- ground surface
**this totals to a loss of 30% of insolation**
What influences climate? - Correct Answer-- oceans, plate tectonics, biosphere
*not just atmosphere*
System Interactions - Correct Answer-- interactions among all climate-influencing
components are complicated to untangle
Feedbacks - Correct Answer-- interactions where one component changing causes
other changes, then original component changes again
Positive Feedback - Correct Answer-- every time cycle is completed, cycle is repeated
ex: when A increases, B changes, A increases again (temp incr, ice melts, temp incr
more)
*doesn't always have to be increase
(temp decr, ice forms, temp decr more)
**hard to break out of cycle**
Negative Feedback - Correct Answer-- when cycle is completed, next time through
cycle, opposite result occurs
ex:
1-when A incr, B decr
2-when B decr, A decr
,(next time through)
3-A decr, B incr
4-B incr, A incr
(back to step one)
**creates a stabilizing see-saw effect**
(neither A or B gets too high/low)
What controls climate? - Correct Answer-- energy/heat is needed to change climate
Insolation - Correct Answer-- energy from the sun that reaches the earth
* "incoming" + "solar" + "radiation" *
- several things affect how much insolation the earth receives
Aphelion - Correct Answer-- variation in insolation
- max distance earth is from the sun
* 152 million km from the sun *
Perihelion - Correct Answer-- variation in insolation
- min distance earth is from the sun
* 147 million km from the sun
Milankovitch Cycles - Correct Answer-- cause variation in insolation
- 3 cycles:
1. Eccentricity
2. Obliquity (tilt)
3. Precession
Geology in the News - Correct Answer--oldest confirmed animal fossil identified
-Dickinsonia
-558 MA --> 15-20 million years before the Cambrian Explosion
-Fossils have been found for decades, but difficult to identify
Why do we care about the climate? - Correct Answer-- climate is influenced by many
parts of the earth
-we deal with climate everyday
-we don't have another planet
Climate - Correct Answer-- average surface conditions on Earth over LONG time scales
(decade minimum)
Weather - Correct Answer-- average surface conditions on Earth over SHORT time
scales
(hours, days, weeks)
, Climate on earth is... - Correct Answer-- complicated, not simple
- varies in different parts of the earth
Eccentricity - Correct Answer-- Milankovitch cycle
- looks at shapes of earths orbit
- switches back and forth from eccentricity min and max ~ every 50,000 years
***BIG IMPACT ON ICE AGE***
- cycle is 100,000 years
Eccentricity Maximum - Correct Answer-- ellipse shape
Eccentricity Minimum - Correct Answer-- circular shape/pattern
Obliquity (tilt) - Correct Answer-- Milankovitch cycle
- tilt of earth on its axis
- "rocks" back and forth by 2 degrees
- cycle is ca 41k years (takes ~ 20k yrs to "rock back") *(where season are on planet)*
How much does the obliquity angle change? - Correct Answer-- ~ 2 degrees
- think of rocking chair
How much does the obliquity angle change the insolation? - Correct Answer--
significantly
- reason why we have opposite seasons in N and S hemispheres
Seasonal Contrast - Correct Answer-- how different summer vs winter temperatures are
High Obliquity Angle - Correct Answer-- completely "rocked" back
- high seasonal contrast
Low Obliquity Angle - Correct Answer-- low seasonal contrast
Precession - Correct Answer-- Milankovitch cycle
- 3-D "wobbling" motion, tilted earth rotating around straight, vertical line (creates circle)
- takes ~ 11k years to get 1/2 way through cycle (1/2 way is when seasons flip months,
full cycle ~ 22k yrs)
How does Atmospheric Gas control climate? - Correct Answer-- atmo-composition
gasses
- greenhouse effect
Atmo-Composition gasses - Correct Answer-- Nitrogen, 78%
- Oxygen, 21%
- rest is greenhouse gasses: can get insolation close to surface and traps some of it
