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
