Upper Geyser Basin
Midway Geyser Basin
| Blue Star Spring, Upper Geyser Basin |
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| A colorful spring in the
Upper Geyser Basin. |
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| Mostly, I took this picture
because it shows the extent of the geyser basin. There are
several thermal features visible in the background. There
are signs warning against straying off the marked pathways
and boardwalks. Apparently, the basin has a lot of hot water
decaying the underlying rock and soil, and there is a danger
of breaking through the crust and falling into scalding
water. |
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| As the water flows away from
the springs it deposits minerals, and bacteria also play a
role, leaving intricate and colorful patterns in the outflow
of the spings. |
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| Grand Prismatic Spring, Midway Geyser Basin |
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| Excelsior Geyser Crater |
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| I was looking for the iconic
Yellowstone view of hot springs cascading over layer of
layer of colorful, built up rock ledges. I think the
pictures I had seen were of Mammoth Hot Springs, a portion
of which is pictured at right. However, I talked to several
people while touring Mammoth who had been there years
earlier, and who said what I saw on this day was nothing
compared to how this area looked 20 or more years ago. The
currents of underwater hot springs apparently have shifted,
and today, there is only a small fraction of the water
volume that flowed in past years. The result is that much of
the Mammoth Hot Spring has dried up, leaving behind these
white calcite deposits. Bacteria in the hot run off was a
primary factor in producing the colorful terraces, and when
the water dries up, the bacteria no longer flourish, and we
are left with the white rocks. |
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| Minnerva Terrace at Mammoth
Hot Springs. Water still flows here. |
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| Outflow from a spring at
Mammoth Hot Springs. |
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| Where water still flows, the
colors still show. |
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| A little different view of
the spring above. |
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