Unit 4

Question 1

Explain how fighting wildfires over the past decades has future implications.

Answer 1

-prevented burning creating excess wildfire fuel
-increases potential intensity, frequency, and size
-increased threat due to growing population and movement into forested areas

Question 2

Describe pyrolysis.

Answer 2

-second step of pre-ignition
-first stage of wildfire
-breaks down larger hydrocarbons prepped by pre-heating (the first step of pre-ignition) and separates them into carbon-rich char, volatile gases, ash, and tar.

Question 3

How does pyrolysis fit into the wildfire process?

Answer 3

Pyrolysis and pre-heating continue throughout the process of a wildfire via the radiating heat of the flames and the gases driven off which prime fuel for the next stage, ignition.

Question 4

What are the two implications of fires in forested areas on climate change?

Answer 4

-CO2 cycling
-release of black carbon and other aerosols

Question 5

Why is it important to maintain a chain-of-custody?

Answer 5

To ensure evidence is valid and hasn’t been tampered with.

Question 6

What is a chain-of-custody?

Answer 6

Legal record of possession used to prove validity of evidence

Question 7

What conditions facilitate well-sorted sand?

Answer 7

Moving water (medium size 0.5mm)
Wind (fine 0.125mm)

Question 8

What are some aspects to consider when determining roundness?

Answer 8

-sharp corners
-original fragmented shape
-angularity
-signs of abrasions

Question 9

What are some aspects to consider when determining sphericity?

Answer 9

-The length, width and thickness measurements.

Question 10

What are some factors that contribute to higher burn percentages in Canadian provinces?

Answer 10

-Coniferous forest (high %) and croplands vs tundra (low%)
-dense vegetation vs breaks in vegetation
-probability of fire enhancing disturbances
-burnable area (think landmass and water)

Question 11

What other reasons contribute to higher percentages of burn?

Answer 11

-firefighting abilities and population for fire reports
-wind
-topography (flat vs mountainous)
-precipitation

Question 12

What does the curve on a grain-size-frequency plot chart indicate?

Answer 12

gentle slope = poorly sorted
steep slope = well sorted

median grain size at 50% passing/retained line

Question 13

What conditions create poorly sorted material?

Answer 13

debris flow sediment and glacial till