Quaternary Environment Flashcards
What are the 3 types of sea level change?
Steric
Eustatic
Isostatic
Describe Steric effect on sea level
Changes in sea level due to temperature, salinity and the dependence of density on temperature and salinity
Describe the Eustatic effect of sea level
Global changes in sea level
Describe Isostatic effect on sea level
Local changes in sea level due to the rising or sinking of land masses
What are 3 types of evidence of climate change?
Lithological evidence
Biological evidence
Geomorphological evidence
Explain Lithological evidence
Evidence found in rocks and sediments
Explain biological evidence
Evidence from fossils, such as diatoms, plant macrofossils, and foraminifera.
Also Pollen stratigraphy
Explain Geomorphological evidence
Evidence from landforms, such as glacial landforms
What are Milankovitch cycles?
Cyclical changes in Earth’s Orbital and rotational parameters
Eccentricity
Changes in the shape of Earth’s orbit around the sun
Obliquity
Changes in the tilt of Earth’s axis of rotation
Precession
Wobble in Earth’s rotational axis
How do orbital and rotational changes influence earth’s climate?
They affect the amount and distribution of incoming solar radiation (insolation), which in turn influences Earth’s climate and the growth and retreat of ice sheets
INSOLATION
INcident SOlar radiATION
How do Milankovitch cycles affect ice sheet dynamics?
Warmer summers due to higher insolation, leads to increased ice melt, while cooler summers allow ice to survive year-round, contributing to ice sheet growth
What are ocean climate change indicators?
1 - Sea Surface Temperature
2 - Ocean Heat Content
3 - Ocean pH
4 - Dissolved Oxygen Concentration
5 - Artic Sea Ice Extent, Thickness, and Volume
6 - Sea Level
7 - Strength of the AMOC
Sea Surface Temperature (SST)
The temperature of the ocean’s surface
Ocean Heat Content (OHC)
The amount of heat stored in the ocean
Ocean pH
The acidity of the ocean
which is increasing due to the absorption of CO2 from the atmosphere.
Dissolved Oxygen Concentration
The amount of oxygen dissolved in seawater
Arctic Sea Ice Extent, Thickness, and Volume
The extent, thickness, and volume of sea ice in the Arctic are declining rapidly, which has significant implications for the regional climate, ecosystems, and human communities
Sea Level
Global sea level is rising due to the melting of glaciers and ice sheets, as well as the thermal expansion of seawater as it warms
Strength of the AMOC (Atlantic Meridional Overturning Circulation):
This major ocean current system, which plays a critical role in regulating global climate, is showing signs of weakening, which could have profound effects on regional and global climate patterns
What are the two main methods for dating climate records?
Radiocarbon dating and Cosmogenic nuclide dating
Radiocarbon dating
Based on the decay of the radioactive isotope carbon-14, this method is used to date organic materials up to around 60,000 years old
Cosmogenic nuclide dating
This method utilises the accumulation of radioactive isotopes produced by cosmic rays in surface materials to determine the time of exposure, allowing dating of landforms and other geological features