By Marius Swart and Ryan Green
None, zero, zip, nada or as they say here in Tanzania… Hamna! That is the extent of our chances of survival if we as humans had to solely depend on our senses. We are terrible at hearing (and much more so at listening) and our eyesight is directly proportional to the availability of light. These are the main senses required for avoiding danger.
That rainy smell…
Having said that, there is something that our most powerful sense is extremely sensitive to. Something so primal to each and everyone of us that despite centuries of urbanised existence we can detect as low a concentration as 10 parts per trillion! That very earthy aroma, which invades your nostrils after a rainstorm after a long warm dry spell, is unmistakeable. Petrichor is the technical term used for the “smell of rain” and it is rather complex.
Something we all know and love
There are two main ingredients that contribute to the all-too-familiar scent of wet soil. The ﬁrst is an oil exuded by plants and is then absorbed particularly in clayey soils only to be dissolved and released as an aerosol with the fall of the ﬁrst rains. The second is called Geosmin and it is a metabolic by product of a bacteria ubiquitously found in soil. Mix these two and the result… an intoxicating aroma that quickens the pulse, make grown men jump for joy, throw caution to the wind and just run around in the rain as if possessed! Or maybe that’s just me…
The promise of rain
Lightning strikes also contribute the sweetly pungent smell of ozone by splitting the nitrogen and oxygen molecules into separate atoms. Another phenomenon associated with rainstorms and lightning are rainbows. Here a double-rainbow adorns the skies and completes the scene…
So the next time it rains…
May you pay particular attention to your nose when next you experience the ﬁrst rains of the season. Also note how your heart rate involuntarily speeds up and a powerful sense of well being suddenly ﬂoods through your whole psyche.
Enjoy. Yours in awareness,
Marius Swart – Guide
Since 1992 Marius Swart has been passionately sharing the splendours of nature with friends and strangers alike. With a penchant for walking safaris he developed a sense of awareness and pace, which provides for an experience of being an observer rather than a participant in Nature’s flow of events. Considering himself as a generalist, as his interests are as divergent as nature itself, he thrives in discovering new wild places and piecing together the components that underpin their cycles. Preferring small groups of guests and quiet concessions, this has led him to some spectacular and unknown regions where interpretation occurs naturally and spontaneously, as the events and behaviour displayed by the wildlife are observed. Of Ruaha, he has this to say:”Besides the astounding biodiversity, topography, incredible elephant and lion encounters, it is the fact that for most part, it is not overrun!” Marius enjoys photography, adventure motorcycling and flying as hobbies when he isn’t “working”.