Rising from the floor of the Great Rift Valley like a monolith is the extinct volcano of Mount Longonot; a stratovolcano located southeast of Lake Naivasha in the Great Rift Valley of Kenya. It is thought to have last erupted in the 1860s. Its name is derived from the Maasai word Oloonong'ot, meaning "mountains of many spurs" or "steep ridges".
Mount Longonot is protected by Kenya Wildlife Service as part of Mount Longonot National Park. That’ why you will have to pay entrance fee at the gate (parking is given as a waypoint to this cache):
Citizen Adult: 300 KES (approx. 3 USD); Citizen Child : 215 KES (approx. 2,15 USD)
Resident Adult: 600 KES (approx. 6 USD); Resident Child: 300 KES (approx. 3 USD)
Non-Resident Adult: 26 USD; Non-resident Child: 17 USD
To be paid cash or by card.
If you want to borrow a walking stick (basic local stick) : It comes for 50 KES per stick. I liked mine especially when climbing down.
I was happy to climb it on a not so sunny day. Nevertheless : in any case it is recommended to start early so that the sun does not hit you so hard. And like in any mountain: Avoid thunderstorms…
It will take for an averagley trained person minimum 4-6 hours to do the long walk (not only up to the rim and down: when you reach the rim you can choose to go around the rim either clockwise or counterclockwise. in my opinion it is easier to walk counterclockwise. There will be another cache for the walk around the rim and for the climb on the ‚real‘ summit of the mountain soon.
A unique feature is the thick forest that lies within the crater of the mountain. The crater rim also provides great scenic views across the beautiful Rift Valley all the way to Lake Naivasha. Major wildlife attractions at Mount Longonot include buffaloes, elands, lion, leopard, bushbucks, common zebra, giraffe and Grant’s gazelles. Thats why at least cachers not familiar with the dangers of kenyan wildlife might be better off with hireing a guide at the gate (approx 3.000 KES or 30 USD should be fine for the long trip around the crater.) But in general it is fine without a guide as well...
Longonot is (as mentioned above) a stratovolcano which contains a large 8 x 12 km caldera formed by vast eruptions of trachytic lava some 21,000 years ago. The current summit cone was developed within the earlier caldera. This cone itself is capped by a 1.8 km crater. Periodic geodetic activity recorded at Longonot in 2004–2006 demonstrated the presence of active magmatic systems beneath this volcano.
As of 2018, geothermal projects struggle to explore the potential.
A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava, tephra, pumice and ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far, due to high viscosity. The magma forming this lava is often felsic, having high-to-intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less-viscous mafic magma. Extensive felsic lava flows are uncommon, but have travelled as far as 15 km (9.3 mi).
Stratovolcanoes are sometimes called "composite volcanoes" because of their composite stratified structure built up from sequential outpourings of erupted materials. They are among the most common types of volcanoes, in contrast to the less common shield volcanoes. Two famous examples of stratovolcanoes are Krakatoa in Indonesia, known for its catastrophic eruption in 1883 and Vesuvius in Italy, whose catastrophic eruption in AD 79 ruined the Roman cities of Pompeii and Herculaneum. Both eruptions claimed thousands of lives. In modern times, Mount Saint Helens and Mount Pinatubo have erupted catastrophically, with fewer deaths.
Stratovolcanoes are common at subduction zones, forming chains and clusters along plate tectonic boundaries where oceanic crust is drawn under continental crust (continental arc volcanism, e.g. Cascade Range, Andes, Campania) or another oceanic plate (island arc volcanism, e.g. Japan, Philippines, Aleutian Islands). The magma forming stratovolcanoes rises when water trapped both in hydrated minerals and in the porous basalt rock of the upper oceanic crust is released into mantle rock of the asthenosphere above the sinking oceanic slab. The release of water from hydrated minerals is termed "dewatering", and occurs at specific pressures and temperatures for each mineral, as the plate descends to greater depths. The water freed from the rock lowers the melting point of the overlying mantle rock, which then undergoes partial melting and rises due to its lighter density relative to the surrounding mantle rock, and pools temporarily at the base of the lithosphere. The magma then rises through the crust, incorporating silica-rich crustal rock, leading to a final intermediate composition. When the magma nears the top surface, it pools in a magma chamber within the crust below the stratovolcano.
Tasks for logging (kindly send answers before logging. Feel free to log without further notice the same minute. But: Logs not fulfilling the requirements will be deleted. Sorry for following a consequent policy on this.
Task 1) S 000° 53.824’ E 036° 28.123’ (see waypoints)
Sign with Emergency Numbers - send me last number on the sign. Possibly a good idea to save these numbers in your phone(s) ; especially when climbing without a guide.
Task 2 (optional) ) S 000° 54.432’ E 036° 27.665’ (see waypoints; same as GZ)
Up the rim - you find a beautiful view to both sides and another place to rest. Kindly take the time to add a photo from gz . Either the view in rift valley or a pic of the beautiful crater.
Task 3) S 000° 54.432’ E 036° 27.665’ (see waypoints; same point as GZ and task 4)
Kindly describe, why this is called a stratovulcano. (some answers/definitons you find in the text above. Kindly reflect additionally on the meaning of the latin word ‚stratum‘ which is behind the name ‚stratovulcano‘.