Amanda Kern Postcards

Lady Knox Geyser The Lady Knox Geyser is named after Lady Constance Knox, the daughter of the 15th governor of New Zealand. It is located in the Wai-o-Taupo area of the Taupo Volcanic Field on New Zealand’s North Island. The geyser was discovered by convicts who were living and working in the region planting the largest man-made forest of pine trees, seen today on the hills beyond the geyser. The convicts were forced to live in rustic accommodations and took advantage of the hot springs for bathing and washing clothes. What the convicts discovered during their first bath, was that there was some sort of chemical reaction between the soap they used for washing and the water below ground which caused the geyser to explode. The convicts also realized that the smaller the hole through which the water could be released, the higher the geyser would spray. The cone formation seen today was originally a ring of rocks put in place by the convicts. Over time the cone has been coated with silicate rich water which solidifies in layers on a daily basis.

For the last 80 years, employees of Wai-o-Taupo Park have induced the geyser to explode every 24 hours at approximately 10:15am using the same reaction principle as the convicts, soap. Lady Knox Geyser is best thought of as a pipe beginning in a reservoir of water beneath the Earth’s surface and opening above ground as a geyser spout. The reservoir of water is heated from below by the Earth’s magma causing a build up in pressure. The heat is not able to convect and once the reservoir pressure exceeds the outside pressure, the geyser blows. It does not blow continually because the water in the spout is colder than the water in the reservoir. Adding soap breaks the surface tension and causes bubbles to rise up the spout. As the bubbles rise they bring with them water from the reservoir allowing the built up pressure to release in an explosion.

Lichenometry on Glacial MorrainesLichens are the ultimate pioneer species, meaning they are the first plant life to grow on recently exposed earth surfaces. Because of this, lichens are useful for determining the time of deposition for glacial morraines and therefore the time of glacial and inter-glacial periods. Glaciers deposit right and left lateral and end moraines as they retreat up valley. Moraines consist of a variety of material, including various sized boulders, which has been churned and piled up by the glacier during retreat. These boulders provide the perfect surface for lichen growth. By measuring and averaging the diameters of the original colonizing lichens across a morraine, an age can be extrapolated using a calibration curve. Difficulties arise when lichens begin to coalesce and determining the diameter of a single lichen becomes impossible. Also, lichen will often grow in a long, linear form and must be avoided in field or data can become skewed.