Labeled version of color enhanced image of snow stratigraphy within the Spurr summit melt pit (see other image in image database without labels). The snow cross section provides a stratigraphic record of the past couple decades. The bold dark layer halfway down as 1992 ash. Above this, there are roughly 14 layers - one for each winter between summer 1992 and 2005. Two thin layers are visible in 1992, perhaps due to snowfall between the August and September eruptions? 1990 and 1991 are also much more prominent than overlying years. This is likely ash from nearby Redoubt eruptions. Extrapolating downward in time (and considering the distance already slumped), the current water level is roughly near the snow layers from the 70's, perhaps even back to the level of the observed pit in the mid-60's. The melt pit/crater must have only filled back in completely with snow in the past decade or so.

Labeled version of color enhanced image of snow stratigraphy within the Spurr summit melt pit (see other image in image database without labels). The snow cross section provides a stratigraphic record of the past couple decades. The bold dark layer halfway down as 1992 ash. Above this, there are roughly 14 layers - one for each winter between summer 1992 and 2005. Two thin layers are visible in 1992, perhaps due to snowfall between the August and September eruptions? 1990 and 1991 are also much more prominent than overlying years. This is likely ash from nearby Redoubt eruptions. Extrapolating downward in time (and considering the distance already slumped), the current water level is roughly near the snow layers from the 70's, perhaps even back to the level of the observed pit in the mid-60's. The melt pit/crater must have only filled back in completely with snow in the past decade or so.

Date: Jun 17th, 2005
Volcano(es): Spurr
Photographer: West, M. E.
URL: avo.alaska.edu/image/view/4730
Image courtesy of AVO / University of Alaska Fairbanks, Geophysical Institute.
Please cite the photographer and the Alaska Volcano Observatory/University of Alaska Fairbanks, Geophysical Institute when using this image.
Full Resolution.