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| Activity Recorded by Data Logger - by Ralph Taylor |
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| Introduction |
Narcissus Geyser has been monitored electronically since 2003 but I have completed analysis of only the data since 2007. As time permits I will analyze the data from earlier years.
The 2007 data is complete from 1105 14 June to 1226 18 September and from 1606 24 September to the end of the year. The 2008 data is complete from 0000 01 January to 0536 12 June (at a resolution of six minutes, so duration data is not available) and from 0820 26 June to 1615 22 September (at 1-minute resolution) and from 1632 22 September to the end of 2008 (at a resolution of 1m6s). The 2009 data is complete from the start of the year to 1542 21 January when the logger was damaged by an unidentified animal and dragged some distance away. Because of the area closure the logger will not be replaced until June 2009.
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Narcissus Geyser is unusual in that it has a pattern of alternating full pool major eruptions and low pool minor eruptions. A major, or full pool, eruption starts after the crater has overflowed for several minutes and continues for eight to ten minutes. A major eruption is followed by a minor eruption after a short interval (typically 2h15m to 2h45m). A minor eruption begins from a low water level (nearly a meter below overflow) and lasts two to five minutes. The minor eruption is followed by a long interval (typically 3h30m to 4h30m) to the next major eruption.
The whole cycle from major eruption to major eruption takes about 6h20m (the mean of the January 2009 data). The range is 5h14m to 7h13m for the major eruption to major eruption interval.
The electronic data shows some rare instances of a cycle with no minor eruption. Some of these instances may be an artifact of the temperature sensor location--some eruptions might not put enough water into the channel that is monitored to register. Some other instances have the second major eruption occurring at about the time that a minor eruption was expected, so probably are not simply a missed minor eruption.
There have been several observations of what might be termed an aborted eruption. In these cases the pool filled to overflow, surging and bubbling occurred, but the major eruption did not occur; instead the pool drained. There is at least one instance of a relatively low-temperature overflow in the electronic data for 2008.
I should also note that the durations measured electronically represent the time that hot water is flowing across the thermistor, which is located about three meters from the west rim of the crater in one of two main runoff channels. The electronically detected durations for the low pool minor eruptions are shorter than visually obtained durations because there is no overflow for the first minute or two of the minor eruptions.
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| Activity in 2010 |
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The overall statistics for 2010 are shown here.
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The interval graph shows all of the recorded intervals to date for 2010. The large excursions in interval represent the alternating major and minor eruptions.
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The next graph plots the intervals from major to minor eruption (blue), minor to major eruption (yellow), and major to major eruptions separately
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The next graph shows the data for the three months preceding the last download. The diamonds mark the individual eruptions and illustrate the alternation of long and short intervals.
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The next graph is the data for the month prededing the last download.
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The interval histogram for the year to date (blue), last month (maroon), and last week (yellow) shows the two distinct peaks in intervals.
Note that in this and the other histograms displayed here the labels shown on the X-axis represent the upper boundary of the class, not the midpoint. Geyser times are traditionally truncated. The graph at the right has class widths of 10 minutes. The bar appearing above the label "2:20," for example, contains intervals from 2h11m through 2h20m.
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The duration graph shows the recorded eruption durations. As with the interval graph, the alternation between short minor an longer major eruptions shows as a broad band on the graph.
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The graph of recent durations shows the individual durations as diamonds, making the two sets of data (minor and major eruptions) more distinct.
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The next graph shows the minimum, mean, median, and maximum intervals for each month. Narcissus Geyser has shown little change in its pattern during the time it has been monitored.
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Activity in 2009
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Activity in 2008
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Activity in 2007
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