Download 2.6.4bcd Ocean Acidification and Sea Level Rise Piper

2.6.4b & 2.6.4c Ocean Acidification and Sea Level Rise
 Ocean acidification is the name given to the ongoing ______________________ in the pH
of the Earth's oceans, caused by the uptake of carbon dioxide (CO2) from the atmosphere.
 Draw the pH Scale 
How does the Acid get into the Ocean in the first place?
 Since the ____________________________ began, it is estimated that surface ocean pH
has dropped by slightly more than 0.1 units on the logarithmic scale of pH, representing an
approximately 29% increase in H+, and it is estimated that it will drop by a further 0.3 to 0.5
pH units (an additional doubling to tripling of today's post-industrial acid concentrations) by
2100.
 These changes are predicted to continue rapidly as the oceans take up more
anthropogenic _________ from the atmosphere.
 Over the last decade, scientists have discovered that this excess CO2 is actually changing
the ________________ of the sea and proving harmful for many forms of marine life. This
process is known as ocean acidification.
Effects on Wildlife
 Corals, mussels, snails, sea urchins and other marine organisms use _______________ (Ca)
and carbonate (CO3) in seawater to construct their calcium carbonate (CaCO3) shells or
skeletons.
 As the pH decreases, carbonate becomes __________ available, which makes it more
difficult for organisms to secrete CaCO3 to form their shells.
 A more acidic ocean could wipe out ________________, disrupt the food web and impact
fishing, tourism and any other human endeavor that relies on the sea.
 The growing acidification of the oceans is a threat to ______________.
 This relatively healthy coral community on Australia's _____________________________
represents the current situation, with atmospheric CO2 concentration of __________ ppm.
Mass bleaching has been observed in many places around the world, and coral reefs
struggle to survive. Coral cover is currently at 60 percent or less of what it once was.
 At an atmospheric CO2 concentration of __________________ppm (which could be
reached before 2050 based on current trends), the accelerated rate of coral erosion would
lead to an overall decline worldwide, as in this location on the Great Barrier Reef. Coral
cover will drop to less than 10 percent of what it once was.
 Once the atmospheric CO2 concentration exceeds ________ ppm, reef ecosystems will be
exceedingly rare or non-existent; robbing many marine organisms of the habitat they need
to survive. Coral reefs worldwide will collapse into rubble, as in this reef that once grew in
an inshore region of the Great Barrier Reef.
Sea Level and Climate change
 Between 1870 and 2004, Global average sea levels have risen _______cm.
 _________ main factors contributed to observed sea level rise.
 The first is thermal expansion: as ocean water warms, it ______________.
 The second is from the contribution of land-based ice due to increased ________________.
The major store of water on land is found in glaciers and ice sheets
 Over the last several decades, evidence of ____________________________ on climate
change has become increasingly clear and compelling.
 Warming of the climate system is well-_______________________--evident from increases
in global average air and ocean temperatures, widespread melting of snow and ice, and
rising sea levels.
 This Aug. 2011 photo shows a flooded road on _______________________, N.C., after
Hurricane Irene swept through the area the previous day cutting the roadway in five
locations. From Cape Hatteras, N.C., to just north of Boston, sea levels are rising much
faster than they are around the globe.
 Extra Extra…now hear this! In the news! ____________________________ tries to wish
away sea-level rise
 US state proposes new law that would ___________ grim projections of a one-metre
sea-level rise by the end of the century
 Some lawmakers will go to great lengths to deny the reality of climate change. But
this week, North Carolina lawmakers reached new heights of denial, proposing a new
law that would require estimates of sea level rise to be based only on historical
data—not on all the evidence that demonstrates that the seas are rising much faster
now thanks to global warming.
 Write why you think NC lawmakers would do this?
2.6.4 d Historical Sea Level Changes- Analyze how sea level has been affected by other earth processes such as glaciations
and tectonic movements. Consider long- and short-term changes.
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Glaciation:
o Sea water removed to form glaciers; glaciers melt
______________________
o Rate:
mm/yr
o Volume change: water
o
!
o During
, a drop
of 106m occurred.
o Melting of Greenland and Antarctic would produce a _________________________
_____________________
o Sea shelf sinks under ice; rebounds when ice melts
o Rate: 0.5-5mm/yr
o Volume change: basin
Change in Water Temperature
o Approximately 2m change in sea level for one degree change in surface water temperature
o Rate: __________
o Volume change: ________
o During Pleistocene, temperatures were ________________________, accounting for _____m lower sea
levels just from ______________________.
______________________
o Addition of new water from volcanic activity; one-way change
o Rate: _____________
o Volume change: ________
Shelf Margin Sinks and Rises
o Affects broad areas, but not worldwide
o Rate: ___________
o Volume change: __________
o _____________________ in Alaska raised the coast by more than 5m!
Change in Rate of Spreading
o Rate of seafloor spreading controls ________________________
o Rate: __________
o Volume change: _________
o The early Atlantic was shallow (____________________________) until the late Cretaceous
(___________________________________________________)
_________________________________
o Reduces basin size;
o Typically a one-way change, sediments can be
returned to continents through the ______________
o Rate: ________
o Volume change: ________
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Subduction
o Loss of _____________________________ or plastered to
continental block; one-way change
o Rate: ________
o Volume change: _________