S n o w

C o v e r

S t a b i l i t y,

A v a l a n c h e

I n i t ia t i o n

a n d

F o r e c a s t i n g

ing testswere combined there was nosignificant differ-
enceincompressionscoreswiththedifferentblades
(p> 0.1).However,theaboveaveragevariabilityofthe
scoresfromoperator 5makeitdifficulttodetectdiffer-
ences (Figure 6).Further comparisons are planned to as-
sess the effect of shovel shape on weak layers closer to the
shovel.

EFFECT OF SHOVEL FACING UP ORDOWN

Some field workers prefer tappinga shovel blade thatfaces
up whereasothers prefer the blade facing down. To assess
this effect, tests were alternated with the two orientations
of the shovel blade.For the tests on 16 January 1996,4-5
pairs of tests were done with a relatively flat metal blade
(Table 6 and Figure 7).On 21 March 1996,15pairs were
done with a smallermore curved blade.Onlythislatter
comparison yielded a significant difference in the number
oftapswiththedifferentbladeorientations(p< 0.05).
Nevertheless,since the mean difference is onlyone tap,
the scores frommatched tests fall within the same range
(easy,easy-moderate, moderate, moderate-hard orhard).
The effect ofshovelorientation appears not toaffect the
scores based on ranges.

CORRELATIONWITHRUTSCHBLOCKSCORES

To determine a possible correlation between rutschblock
scoresandcompressionscores,three compression tests
weredoneadjacent tooneortworutschblocktests.At
some of the sites,more than one weak layerfailed,each

Figure 6 Effect of different shovels on compression scores

79