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Test slope reactive

Location Name: 2.5k west of peak 8740 Region: Independence Lake Area Observation Date & Time: Wednesday, January 16, 2019 - 13:00
Location: 39.428274, -120.423372 See map: CalTopo	Is this an Avalanche Observation?: Yes Conditions Alerts: Avalanche Activity Recent Loading Recent Loading›More Than a Foot of New Snow Terrain Alerts: Slopes Steeper than 30 degrees Terrain Matches the Advisory

Observation made by: Public

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Observation

Description of Snow, Weather, and Avalanche Conditions:

In a large wind deposit with a slight overhang shooting cracks were observed on a second pass on a snowmobile. The snowmobile was going slow on this terrain feature looking for instabilities. After seeing shooting cracks, snowmobile made a turn on top of the small wind feature 3-5 feet from the edge, intentionally trying to trigger the windloaded feature. Fracture propagated and released just as thought.

Test slope avalanche on small wind loaded cornice

Shooting crack from snowmobile ski tip

Shooting crack from snowmobile track

Snowpack Details

Persistent Weak Layers:

Not observed

Terrain Details

Terrain: elevations:

Near Treeline

Terrain: aspects:

Avalanche Details

Avalanche Type:

Cornice

Failure Plane/Weak Layer:

Storm Snow

Trigger

Trigger:

Snowmobiler

Trigger Modifier:

Intentionally Triggered

Terrain

Aspect:

Northeast

Starting Elevation:

near-treeline

Size

Destructive Size:

D1 Relatively harmless to people.

Relative Size:

R1 Very Small

Crown Height:

1 ft

Avalanche Width (Average width):

25ft.

Avalanche Length (Vertical Run):

10ft.

People Involved

Number of people caught:

Number of partial burials:

Number of full burials:

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Test slope reactive

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Test slope reactive

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