Hellens gasses heavier then air carbon dioxide that

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: bris flows • Mud flows • Other effects (not covered here, but - sometimes the blast isn't just up, but sideways (St. Hellen's?) - gasses: heavier then air, carbon dioxide that hugs the grounds still important to be aware of): - landslides - damming of streams floods - fires (heat from lava - long term climatic effects. Significance of volcanic hazards to sustainability: Costa Rican coffee plantation established on Volcanic processes ultimately affect global economy soil developed from weathered volcanic material - much is glassy and can weather quickly, this can releave organic nutrients to plants (overall positive) - can be good and bad to human pop Negative effects: crops fail, animals die, people displaced - assumption of risk (where ppl live) Positive effects: renewal of soil nutrients ________ (weathering of ash and organic matter from burned vegetation) - it is a natural thing (volcanos) The awareness of potential effects of volcanic activity on the Earth system (directly or indirectly) can improve the balance of positive and negative impacts on human populations (healthy respect for the nature of eruptions is a good thing). Primary Volcanic Hazards: Lava Flows _____-viscosity lava flows can Low travel up to 100 km from vent. Danger does not become less with distance from vent (the temperature of some lavas can reach 1100 oC) Limited loss of life, but damage tends to be severe - mafic: cool form basalt (can outrun/ we are faster) - retain their heat with distance - limited life - Obviously, lava eruptions can not be prevented, but can sometimes divert flow or halt the advance of lava locally by chilling its boundaries. 8 Pyroclastic Activity Materials including ash, pumice, volcanic bombs, and fragmented debris (collectively called tephra) are propelled from vent at high velocities ________ - pulverized material coming out - blobs come out and cool in the air Three types of events are particularly hazardous: Ash falls Lateral blasts Pyroclastic flows Primary Volcanic Hazards: Ash F...
View Full Document

This document was uploaded on 02/25/2014.

Ask a homework question - tutors are online