Lecture 4: Disaster Energy Sources Flashcards
Magnitude
Assessment of size of an event
Has units
Proportional to energy
Frequency
Number of events in a given time interval
Units of energy (4)
Newton, Erg, Joule, Kilowatt
5 fundamental sources of disaster energy and relative abundances today
- Kinetic energy from gravitational accretion of proto-earth
- Frictional heat and kinetic energy due to gravitational differentiation of materials with different density
- Kinetic energy from nuclear and coulomb forces of radioactive (radiogenic) decay, releasing alpha and beta particles
- Kinetic tidal energy
- Heat energy from solar nuclear synthesis
Intensity
Assessment of impact of disaster
Observation by people, property damage, death
Unitless - ranking
Scales
Used for rapid communication
Units are category
Often intensity (not magnitude) or both
Should be universal in applicaiton
Examples of scales (3)
- Volcanic explosively index
- Proposed Tsunami (Papadapoulus-Imamura) scale
- Saffir-Simpson Hurricane Intensity scale
Two important energies for natural hazards
- Potential energy: ready for work
2. Kinetic energy
Radioactive decay
Spontaneous emission of particle from nucleus
Transforms atoms from one isotyope to another
Internal (endogenic) primary sources of energy (3)
- Kinetic energy from gravitational accretion of proto-Earth
- Frictional heat and kinetic energy due to gravitational differentiation of materials with different density
- Kinetic energy from nucelar and coulomb forces of radioactive decay
External (exogenic) primary sources of energy (2)
- Kinetic tidal energy
2. Heat energy from solar nuclear synthesis
Newton
Force: mass x acceleration
Erg
Work: mass x acceleration x distance
Joule
Work: mass x acceleration x distance Force of 1 Newton over 1m 10 million ergs 1/4 calorie Over time: watt
Kilowatt
Power: (mass x acceleration x distance)/time
Accretion
Formation of Earth by gravitational pull of dust particles
Gaining heat
Source of energy for blizzards?
Sun
Hazards from Earth’s internal energy (3)
EQ
Tsunami
Volcanic eruption
Hazards from Solar Energy (5)
Weather related: meterological storm, flood, drought, wildfire
Geological: magnetic storm
Hazards from Gravitational Energy (2)
Mass movement
Snow avalanche
Hazard from Impact Energy
Impact with space objects
Earth’s capture of energy from Sun
10^18J
About factor 100 higher than heat from Earth’s interior
Does not penetrate far below surface
Energy from Earth’s Interior
8 x 10^20 J/year
5 B years ago: 40 x 10^20 J/year
