Colorimeter data for the summit water lake at Kīlauea Volcano, Island of Hawaiʻi, 2020

In 2018, a large effusive eruption on the lower flank of Kīlauea Volcano was associated with collapse and subsidence of the summit caldera floor (Neal and others, 2019).  The bottom of Halemaʻumaʻu, a crater nested within the summit caldera, subsided by more than 500 m.  In July 2019, water was observed ponding on the deepest part of the Halemaʻumaʻu crater floor and the water rose and enlarged in area steadily over the next 16 months (Ingebritsen and others, 2020; Nadeau and others, 2020; Patrick and others, 2021).  During the course of the rise, the lake surface appearance was highly dynamic and segmented, showing regions of variable color that changed from day to day (Nadeau and others, 2020).  In June 2020 staff at the U.S. Geological Survey’s Hawaiian Volcano Observatory began regularly collecting colorimeter data (quantitative measurements of color) of the water surface as part of routine monitoring, which included water level measurements (Patrick and others, 2021), photo documentation, and direct water sampling (Peek and others, 2023), augmenting existing monitoring by geophysical instruments, webcams and thermal cameras (Patrick and others, 2022).  Data collection on the water lake ended in late December 2020, when a new eruption in Halemaʻumaʻu filled the crater floor with lava, rapidly boiling off the lake (Cahalan and others, 2023). 

In this data release, we include routine colorimeter measurements of the water lake surface collected from the crater rim using a Minolta CS-160 colorimeter.  Measurements were generally made in several areas of the lake due to the spatial variation in color across the surface.  Previous work on volcanic lakes has shown that lake color is closely associated with water chemistry, which in turn offers insights into lake dynamics (Christenson and others, 2015; Ohsawa and others, 2010).  Colorimeter data are used here to measure the surface color in an objective, quantitative manner (Smith and Guild, 1931).  These data may be useful in future studies relating lake color, chemistry, and hazards. 

References
 
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