The Marine Biogeochemical Cycles: Carbon, Nitrogen, Phosphorus, Silicon, Sulfur, and Iron
LECTURE 12: The Biological Carbon Pump and Microbial Carbon Cycling
Key Concepts
- Biological Carbon Pump: Mechanism by which the ocean absorbs atmospheric CO2 through phytoplankton photosynthesis. When phytoplankton die, some carbon sinks as detritus, transporting it from the surface to the deep ocean. Factors like microbial degradation and zooplankton activity affect the efficiency of carbon transfer.
- Particulate and Dissolved Organic Matter (POM and DOM):
- POM (>0.7 µm): Consists of cell biomass
A Comprehensive Guide to Earth Sciences: From Rocks to Volcanoes
Discharge and Erosion
Discharge (m3/s) = width (m) x depth (m) x velocity (m/s)
Erosion produces stream load, the combination of:
- Bed load (gravel, sand – roll, bounce, slide)
- Suspended load (silt, clay – float)
- Dissolved load (dissolved minerals)
Flood Management
Flood Prevention: Try to control the flow and stage of water.
Flood Adjustment: Policy and lifestyle shift to account for local flooding.
Groundwater and Aquifers
Porosity: Proportion of earth material made up of spaces (that can fill with water)
Read MoreHydrological Processes and Water Management
1. What is the hydrological cycle and how can water balance be quantified?
The hydrological cycle is the water’s cycle caused by solar energy. It can be quantified by the following equation: P = Q + AE +-AW (precipitation= runoff + actual evapotraspiration +-Changes in water storage (surface, soil water, ground water)). In this cycle, we have to consider also the change of state of water aggregation, from ice to liquid and vapour, and also snow, hoarfrost, etc.
2. What are both catchment and management
A Journey Through Earth’s History: From Formation to Present Day
1. The Earth: A Constantly Changing Planet
Climate Changes
Throughout Earth’s history, there have been alternating warm stages (characterized by a strong greenhouse effect) and cold stages (glacial periods).
Eustatic Changes
These are changes in sea level. When seas rise, they cover continents, a phenomenon known as marine transgression. When they fall, previously submerged land becomes exposed. This is called marine regression.
Paleogeographic Changes
These are changes in the distribution of continents
Read MoreEnvironmental Issues: Atmosphere, Soil, and Energy
Layers of the Atmosphere
Troposphere
The layer of Earth in contact with the surface, its average thickness is 12 km. It contains all weather and the majority of gases that form the atmosphere. This layer meets the conditions for the development of life on Earth.
Stratosphere
This layer extends from the troposphere to a height of 50 km. It is formed by layers of gases and here we find the ozone layer that protects living things from the damaging ultraviolet rays from the sun.
Ionosphere
This layer reaches
Read MoreA Comprehensive Guide to Rock Features and Types
Chapter 1: Features of Rocks
1. Adherence & Cohesion
This refers to the bonding force between particles. Rocks are classified based on their bond or cohesion:
- Consistent: Require significant effort for grinding.
- Friable: Crumble easily.
- Loose: Grains formed by loose sand.
Rocks can also be classified based on the source of their adherence:
- Rocks added: Adherence is achieved by the beads being attached to each other (e.g., granite).
- Rocks agglomerated: Adherence is achieved by means of a cement (clastic)