What You Need and
“Things To Be Aware Of”
You will need a bottle of water. Be careful of passing cars.
Background
Is that title punny enough for a soil based earthcache? I had to
dig real deep…
The soils of the Taieri Plains are amongst the most fertile in
New Zealand. This fertility coupled with a "milder than Dunedin"
micro-climate allows a range of different agricultural and
horticultural activities to take place. The fertility is due to the
fact that the area is a large flood plain (300 sq km) for the
Taieri and Waipori Rivers. Historically these rivers would flood
distributing fertile silt across the land. Today, this is somewhat
of an inconvenience and the Taieri has been stopbanked, preventing
most flooding and the Waipori is under hydroelectric dam
control.
View across the Taieri Plains
Soil is formed in a process called pedogenesis or soil
evolution. It typically occurs over a very long time - the rate of
formation is influenced by climate, living organisms and the
composition of parent material (eg rock). Generally, weathering of
parental material occurs first, this allow colonisation by lichen
and moss and the formation of a simple soil. Further weathering and
succession (and decomposition) of plants eventually may lead to the
development of a rich soil. The process may take more than hundreds
of years - in some areas soil is known to accumulate at a rate of
2.5cm every 100 years.
Soil texture describes the relative proportions of clay, silt
and sand in the soil. Clay (< 0.002 mm in size) feels sticky
when wet, silt (0.02 - 0.002 mm) feels floury and sand (2.00 - 0.02
mm) feels gritty. The proportions of these can give an indication
of the how the soil was formed and its current suitability for
different applications.
The 12 Soil Texture Classes
Logging
Requirements
0. Preface any email with GC28FKD Getting the Good Dirt in the
subject line and title and clearly note the question number and
answer. You don't need to wait for a confirmation email to log but
you might be asked for more info if your answers are slim.
1. Using the protocol supplied above work out the textural class
of the soil (eg sandy loam). Email this.
2. Use the expanded textural triangle to take your answer from
question one and find out the approximate percentages of sand, silt
and clay. Email this.
3. What is the scientific name for soil formation? Email the
answer.
4. An uploaded photo of task one being completed would be nice
but not compulsory.
Bonus Question: This location looks apparently random but
was chosen for a slight geographical anomaly. Flipping through
waypoint or position attributes may reveal this. Bonus 3 points to
the first logger to upload a picture of this unusual feature of the
location - depending on satellite position this may not work every
day!
Key
Sources
Wikipedia articles on soil
formation and the
Taieri Plains
NASA's Goddard Space Flight Center website on soil
texture(+ credit for texture protocol)
2010 Stegan’s
EarthCache Masters Programme
Since it is not very feasible for many NZers to easily get more
than two states for the earthcache.org masters programme and
therefore not get past Bronze I’m running my own one on a
number of Earthcaches that I plan to release this year (all things
being equal) with the following points system:
5 points: First to find
3 points: 2nd to find
1 point: Logging a find
1-5 points: Special bonus questions.
Shared points for joint finds.
At the end of 2010, I’ll issue certificates for 1st, 2nd
and 3rd and the first place getter will be awarded a geocoin. If I
feel richer and/or it looks like this is popular I’ll upgrade
the prizes.
Updated information and Leaderboard at: Stegan’s
Earthcache Programme