Background lecture

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Dendrogeomorphology

• Background lecture
• Various examples
• Web images
• Old business
• Dating, discovering previously unknown earthquake
  on southern San Andreas
• New business
• Current research on Parícutin eruption
• Prep for Sunset Crater

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How Dendrogeomorphology

• Any unusual change in ring growth
• Decreased/increased width growth
• Decreased/increased ring wood density

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How Dendrogeomorphology

• Any unusual change in ring growth
• Decreased/increased width growth
• Decreased/increased ring wood density
• Death/initiation date

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How Dendrogeomorphology

• Any unusual change in ring growth
• Decreased/increased width growth
• Decreased/increased ring wood density
• Death/initiation date
• Reaction wood/abrasion scar

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How Dendrogeomorphology

• Any unusual change in ring growth
• Decreased/increased width growth
• Decreased/increased ring wood density
• Death/initiation date
• Reaction wood/abrasion scar
• Ring chemical changes
• Nitrogen?
• Strontium?

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What Dendrogeomorphology

• Earthquakes 1989 Loma Prieta

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What Dendrogeomorphology

• Earthquakes
• Volcanic eruptions

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What Dendrogeomorphology

• Earthquakes
• Volcanic eruptions

• Other ground
• Mud/debris flow, rockfall
• Soil creep

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What Dendrogeomorphology

• Earthquakes
• Volcanic eruptions

• Other ground
• Mud/debris flow, rockfall
• Soil creep

• Water
• Shoreline
• Riverine

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What Dendrogeomorphology

• Earthquakes
• Volcanic eruptions

• Aeolian
• Great L. dunes

• Other ground
• Mud/debris flow, rockfall
• Soil creep
• Water
• Shoreline
• Riverine

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What Dendrogeomorphology

• Earthquakes
• Volcanic eruptions

• Aeolian
• Great L. dunes

• Snow
• Neo advances
• Avalanches (Dexter)
• Permafrost
• Ice ramparts, jams
• http//www.neatorama.com/2007/05/31/frozen-waves/

• Other ground
• Mud/debris flow, rockfall
• Soil creep
• Water
• Shoreline
• Riverine

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What Dendrogeomorphology

• Earthquakes
• Volcanic eruptions

• Aeolian
• Great L. dunes

• Snow
• Neo advances
• Avalanches (Dexter)
• Permafrost
• Ice ramparts, jams
• http//www.neatorama.com/2007/05/31/frozen-waves/

• Other ground
• Mud/debris flow, rockfall
• Soil creep
• Water
• Shoreline
• Riverine

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Why Dendrogeomorphology

• Basic understanding of surficial processes
• Dates, therefore frequency of events
• Location, areal extent
• Magnitude
• Temporal-spatial coherence
• E.g., volcanism related to seismicity?
• Medicine Lake Highlands

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Why Dendrogeomorphology

• Basic understanding of surficial processes
• Dates, therefore frequency of events
• Location
• Magnitude
• Temporal-spatial coherence
• E.g., volcanism related to seismicity?
• Medicine Lake Highlands
• Future prediction not a goal so much

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Dendrogeomorphology Fundamentals

• Uniformitarianism
• Events affect trees similarly
• Absolute conditions need not be similar
• Limiting factors
• Events change what limits tree growth
• Site selection
• Certainly not random
• Carefully considered

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Dendrogeomorphology Fundamentals

• Crossdating
• Annual precision a strength of dendro
• Getting close could be misleading
• Sensitivity
• Enough to facilitate crossdating
• Not too much, mimic geomorphic signal
• Replication
• How many trees with geomorphic signal?

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Dendrogeomorphology Fundamentals

• Control (expectation)
• Growth prior to event
• Growth of other trees after event
• Departure from expectation
• Also caused by climate, ecological events
• Mapping often critical
• Calibration to known event would be nice
• Vanishing evidence

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DendrogeomorphologyQuadruple Junction

1. Geomorphic process, frequent and recent
2. Must damage trees without destroying evidence
3. Must be old trees, with crossdating
4. Compelling hazard to humans

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DendroseismologySouthern California

1. Recent event (1857), previous event thought to
   be within 200 years
2. Living trees show 1857 event
3. Long-lived pines and firs
4. Millions of people living nearby, some right on
   the San Andreas

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• Pool Tree
• Huge Jeffrey
• No top
• Sag pond pool

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• Lone Pine Canyon
• Huge Jeffrey
• No top
• Right on fault

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• All Trees
• Control chronology robust
• 1812 1857 drought years?
• Nine event trees
• Pines, firs
• Confirm 1857, show 1812
• Span 12 km of fault

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San JuanCapistrano

• 60 km south of Wrightwood
• Big earthquake in 1812, Dec. 8.

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Interpretation

• Short segment ruptured, but longer than our trees
• The word irregular made it in title
• 1812 45 yrs
• 1857 146 yrs
• 2003

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Another Interpretation

• Seismic ruptures displace stress, rather than
  eliminate it (SciAm, Jan. 2003)
• Stress displaced to the north?
• 1812 southern California 45 yrs
• 1857 central California 49 yrs
• 1906 San Francisco
• When will south start again?

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DendrovolcanismSunset Crater

1. Last event not very recent (AD 1064?)
2. Trees from archeo collections show that event
3. Crossdating legendary
4. Sinaguans lived nearby
5. Calibration from Parícutin 1940s?

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Questions About Sunset

• Nature of association of event trees with
  eruption?
• Eruption perhaps a lengthy event?
• Did ash truly improve environmental conditions
  for Sinagua?
• Blank Sand, by Colton?

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Parícutin, Mexico

• Cinder cone, similar to Sunset
• Well known modern event
• 1940s-50s eruption
• Lava, ash fall well-mapped
• Forested area, then and now
• Perhaps could serve as a calibration for Sunset

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Parícutin

• Big, young pines
• Most start in 1960s
• A few start in 1930s
• Some old stumps
• Dating not great, but passable
• Measure widths and elements
• S, P

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• Interpretation (so far)
• Clear visible effects on this tree
• P and Ca response might be indirect ? soil pH
  changes
• Either way, a useful chemical variable
• Will this show up in Sunset Crater archeo wood
  collection?
• Could refine start date of eruption
• Could better define length of eruption

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Dendovolvanics Mount St. Helens

• A virtual dendrogeomorph playground
• Recent eruptions
• Lots of old trees
• Lots of people

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1842
1843
1845
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• Interpretation
• 1842 event trees were in lahar surge
• Formation of Goat Rocks Dome began shortly
  (within 10 years) before that
• Petrologic cycle of dacite-andesite-dacite

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How Dendrogeomorphology

• Any unusual change in ring growth
• Decreased/increased width growth
• Decreased/increased ring wood density
• Death/initiation date
• Reaction wood/abrasion scar
• Ring chemical changes
• Nitrogen?
• Strontium?

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What Dendrogeomorphology

• Earthquakes
• Volcanic eruptions

• Aeolian
• Great L. dunes

• Snow
• Neo advances
• Avalanches (Dexter)
• Permafrost
• Ice ramparts, jams
• http//www.neatorama.com/2007/05/31/frozen-waves/

• Other ground
• Mud/debris flow, rockfall
• Soil creep
• Water
• Shoreline
• Riverine