Facts about Mt Kenya

Introduction

Mount Kenya is a volcano, about 3 million years old, whose base diameter is about 120km. The main peaks are the Batian and Nelion. They are composed of nepheline-syenite which is a coarse-grained, intrusive igneous rock. The rocks of the lower slopes are of various different lavas and agglomerates. Eruptions from satellite vents produced such features as Ithanguni, Mugi Hill and the Giants Billiard Table. During the period when global climates were significantly cooler than they are today and large ice sheets covered much of northern Europe and Canada, the glaciers on Mt. Kenya extended down to about 3000m. The erosive work of these glaciers was responsible for cutting the deep U-shaped valleys around the slopes of the cone. Within the valleys are found terminal moraines; these curved ridges of boulders and gravel represent the load of eroded material carried within and under the glacier. Moraines provide evidence as to the former extent of the glaciers, of the different episodes of glaciation, and of the various stages in the retreat of the glaciers. At present the glaciers are retreating at an accelerating rate; the ice is also becoming thinner. It has been estimated that if the present trend continues, in 25 years there may well be no permanent ice left on the mountain. Since records were first made in 1893, seven of the eighteen glaciers then recorded have disappeared.

Location

Mount Kenya is located on the equator. Magnificent cliffs and glaciers protect the highest peaks of Nelion (5188m) and Batian (5199m). The third summit – Point Lenana (4985m) is also glaciated but accessible to walkers.

Vegetation and Wildlife

Mount Kenya has different fauna from Elephants to rock Hyrax and a variety of birds. The floral is also very wide from the mountain forest, bamboo, heather to tussock grass and the everlasting flowers.

Weather, Climate and Seasons

Lying on the equator Mount Kenya is affected by the passage of the Inter tropical Convergence Zone, which brings with it the main rainy periods. The highest rainfall occurs between late March and the middle of May, and slightly less between late October and mid December. Maximum rainfall occurs in the forest belt and on the south-east side of the mountain where it reaches 2500mm per year at 3000m. Precipitation decreases with altitude and is about 700mm per year at 4500m. Rain and, higher up, snow can however be encountered at any time of year – even in the driest periods (January and February). Normally the drier seasons are associated with clear, dry weather which can last for many days on end. The best weather is generally in the mornings, and convectional rainfall, if any, tends to come in the mid-afternoon.

Temperatures vary considerably with height and with time of day. On the plains surrounding Mount Kenya the average day temperature is about 25°C. At 3000m frosts can be encountered at night while day temperatures range from 5 to 15°C. Night time temperatures on the summit are well below freezing. The south-facing side of Mount Kenya receives more sunshine in the December to March period. During this time rock climbs are “in-condition” and snow and ice climbs gradually deteriorate. In the June to October period the north-facing rock climbs and south-facing ice climbs are best.