Busa di Manna, the Sinkhole

Busa di Manna is a sinkhole in San Martino di Castrozza plateau which, besides producing incredibly low temperatures, is also a good model for swallowing Spiritus Mundi.

You may have already read on this site that Alchemy is not a polarity game, but a game of attraction. Nevertheless, it is not an attraction between contraries or complementaries but based on densities. We are always before a less dense Mercurius/Secret Fire/Spiritus Mundi attracted by a denser one, as opposed to the atmospheric models, and that’s why it is so difficult and hardworking to extract it from raw matters. And that’s also what an alchemical magnet is for.

But the Spiritus Mundi ( the name given to Mercurius when lingering in the atmosphere) has also another peculiarity, I retake here a previous post on Clovis Hesteau de Nuisement (2): “…during the day, from the earth frame of reference, Secret Fire/Spiritus Mundi is not allowed to arrive to the ground, but limits itself to linger in the higher atmosphere layers. It is only during the night when the Sun is on the other side of our planet, that Secret Fire can finally descend to the ground to go deeper and deeper. In fact, Secret Fire seems to love dark conditions. A sunny day mostly implies cooking or magnetization, that’s to say the destruction of the raw matter by exposition to hot and a successive cold…“. The paradox is that the Sun and Stars are huge producers of Secret Fire/Mercurius. So how does it come that Spiritus Mundi eventually manage to land? But let’s look at our natural sinkhole before trying an answer.

The karst plateau of San Martino di Castrozza is a mountain desert of utter beauty, of about 50 sq. km., crowned by Dolomite peaks which are borders to the Italian regions of Trentino and Veneto.  Like a real crown, beyond the peaks, the plateau precipitates into the woods below, which in the nearby of Monte Agner reaches a vertical drop of one kilometer. In a poetic way, it can be defined as a huge stone castle emerging from the Paneveggio forest.

And from the Paneveggio forest, the violin wood (1), as a matter of fact, it comes almost all the humidity and winds going uphill the natural Dolomitic stone castle. I have known the place since my childhood, while writing I can recollect my mother forcing the family to neglect the cableway and instead climb up the old track from San Martino village, which was quite an adventure for us children under ten. She tempted us saying ” today I’ll bring you the moon”. And, indeed, she could not be more right.

But what my mother didn’t know was that the plateau was not a compact sedimentary rocky bulk, but the subsurface was actually traveled by a karst system like a Gruyère cheese. The karst system has been detected but not yet explored, due to the lack of a visible entrance hole, but sinkholes. Just 20 km. south-east San Martino plateau there spread out the Piani Eterni, or eternal planes (because of their vastness ), a huge caves system that they only recently started to explore. An expedition in 2014 proved that the system plunges vertically to 1052 m. under the sea level and stretches horizontally for kilometers absorbing the falling waters.  At present, there is no evidence that San Martino karst system runs along the same lines, though.

otherwise, they are simple basins ( in fact, as you can see in the image on the side, there are other deeper basins in the plateau). Busa di Manna, 2540 m. from sea level, is closely monitored by scientists and meteorologists as the weather pattern is specifically typical of elevated sinkholes. Winter temperatures – but only in the bottom of the sinkholes – can reach -50° C (winter 2015), a feature shared with the Carinthian Hohentauern sinkholes, but San Martino di Castrozza is much closer to the Mediterranean. These sinkholes are known, among Italian meteorologists, as “fabbriche del freddo” or icy factories.

In winter 2015 in Busa di Manna it has been measured a crazy difference of 20 degrees in just 12 vertical open meters: they are miracles of sinkholes. The frozen air only stagnates in sinkholes, a bit like the rainwater that collects in puddles when it rains. If you exit the sinkhole at -40 ° C and move 100 meters maybe you’re not even at -20 ° C. Nevertheless the climate of the desert mountain gets deeply affected, because these extreme “ice factories”, though not in the open atmosphere, are however existent and not insulated. The weird is that the hotter the summer seasons in the forest below, the colder the “icy factories” sinkholes in winter. Among the other monitored sinkholes in San Martino plateau Busa di Manna is almost always the cold-top winner.

The first research on cold-pool formation in valleys and basins (for instance Geiger 1965) emphasized the role of long-wave radiation loss and the downward flux of sensible heat from the overlying atmosphere to counter this loss. This produced a cold-air layer over the slopes, which subsequently drained downslope into the nascent cold-air pool, causing it to grow and cool.

The reader can find the current state-of-the-art research in the exhaustive mathematical model Formation of Extreme Cold-Air Pools in Elevated Sinkholes: An Idealized Numerical Process Study by Günther Zängl, research on elevated sinkholes phenomenon, considering almost the extreme situations in the Gstettneralm and Peter Sinks sinkholes.  The model results indicate a number of necessary preconditions for the formation of an extreme cold-air pool in a sinkhole assuming the surface are to be covered with freshly fallen snow above a height of 1000 mm, while the case I’m examining in Busa di Manna presents bare rocks and melting snow.  Below I provided an essential and brief summary of Zängl research:

“Apart from undisturbed clear weather, the small heat conductivity of the ground and an effective mechanism drying the low-level air during the cooling process are required. The importance of the heat conductivity results from the net cooling of the ground is only a small residual between the net radiative heat loss and the ground heat flux. Downward long-wave radiation is confirmed. The most notable difference between the model results and the observations concerns the vertical temperature profile in the sinkhole, which tends to be smoother in the model than in reality.

The larger ground–air temperature differences occur in the cloud-free regions where the net radiative heat loss of the ground is much larger. The drying is mainly achieved by ice cloud formation and subsequent sedimentation of the ice particles. The air in the center region of the sinkhole is now more than 15 K colder than outside, which in turn explains the virtual absence of katabatic winds in the inner part of the sinkhole. During undisturbed clear nights, the air in closed sinkholes cools very rapidly around sunset, followed by a more gradual cooling in the night proper. The cooling rate of the basin air is found to be close to the net radiative cooling rate around sunset but much smaller in the second half of the night, implying that a significant opposing heat source is present. Clements et al. (2003) also found that downslope flows along the side slopes of the basin are only of minor importance because they are hampered by the extreme static stability within the cold pool. Moreover, turbulent vertical fluxes of sensible heat were shown to be negligible except for a short period after sunset, indicating that the cooling of the basin air is maintained by radiative heat flux divergence. The absence of significant sensible heat fluxes also suggests that the net radiative heat loss of the surface is nearly balanced by heat conduction from the ground. The presence of a positive feedback effect of the cold pool on the downward long-wave radiation is confirmed, the ground heat flux is the leading term opposing the net radiation in all cases”.

Interesting the confirmation of downward long-wave radiation. On the left is a graphic taken from the Zängl model, FIG. 10: “Downward longwave radiation” (contour interval 5 W m -²) at 0800 LT for simulations (a) Reference simulation, (b) 10-K-colder initial temperature profile, (c) Surface parameters for grassland instead of snow, and (d) Reisner1 cloud microphysics. The model for grass is on the top right. But Zängl has not provided a model for melting snow-bare rocks, Busa di Manna’s summertime environment.

In my July exploration (in which you can watch a summarizing video at the top) I can confirm the scarce wind condition, while on the upper edge of the basin the wind was easily detected. The busa can be seen on the right of track 707 Rifugio Rosetta-Val Canali ( about an hour hiking from Rifugio Rosetta), and it is recognizable from the form of the broad and deep basin, the scattered and still not melted snow and the temperature monitoring system mounted on top of a stirrup positioned in the lowest point. During the descent from the top track to the real Busa a decrease in temperature was immediately detected, which became even almost scary in the last ten vertical meters. But, once on the bottom, surprisingly immediate acclimatization took place and I did not feel the slightest need for a sweatshirt (I spent there more than an hour in a t-shirt). On the bottom of the basin, I felt the air was highly ionized, though static.

Since it is a sinkhole,  the presence of surface openings for water disappearance in the underground was assumed. In fact, I quickly found an aperture (frozen inside and probably a remnant of an ancient cave) and a lower slot still doing its swallowing melting snow duty.

San Martino di Castrozza area is known to be exceptionally thunderstorms during summer, with almost clear winter instead. But those who are accustomed to the area, also know that summer rainy weather typically starts in the early afternoon ( with typical afternoon hailstorms and thunders), then leaves wonderfully clear sky conditions from the night on till the noon of the day after, and such deep blue sky conditions are hardly seen in other Alps zones.  In fact, due to tradition, while my trip was coming to an end clouds were already climbing from the woods up the outer walls of the plateau. And shortly after they actually became so heavily foggy that to be cut by a knife ( to be honest only a dimming red jacket led me out of that grey hell).

To this extent, many alchemists will affirm that our Spiritus Mundi catching sky conditions should stay absolutely clear and bright. And they are not wrong, but they also should know that the Moon is responsible for taking the Spiritus Mundi down to the earth, after having spent the daytime lingering in the higher atmosphere layers. And there is no cleaner sky than the night sky after an afternoon thunderstorm, exceptionally free from most atmospheric dust and nitrogen oxide, probably the same dust some alchemists claim to be able to collect from the Sun, but still, atmospheric dust and nitrogen oxide, though strongly ionized. This is not bad, alchemically speaking, but this claimed “solar powder” very hardly can be called Spiritus Mundi.

So we know the Spiritus Mundi gets condensed in cold conditions, more exactly in its way from hot to cold regions (4), although some affirm it is attracted by natural fire as well. We know Spiritus Mundi loves to condense fitting into the slots of lower places. We also know it fails to reach the earth’s surface during sunlight and tends instead to fall during clear moonlight. We are acknowledged that Spiritus Mundi hates wind, but loves strongly ionized places. To cap it all, it definitely loves rocky mountains, as well as desert conditions. Eventually, we know that the most ancient shrines and temples were provided with holes and caverns in the ground and with running underground stream water.

To conclude a short examination of the name Busa di Manna: busa stands for “basin” in both Trentino and Veneto. Manna is a rather bizarre name for a Dolomitic sinkhole, in fact, manna is the definition of the weird substance miraculously supplied as food to the Israelites in the wilderness, and felt from to sky (Exod. 16). I could not investigate more among the locals, those interviewed failed to provide a valid reason for the name. Of course, I don’t mean to rely on the poetic allure of the name manna to confirm my idea. But indisputably this has always been the denomination of the sinkhole, which roughly ( that’s to say natural, not purposely built) appears to offer many interesting features of a good alchemical natural condenser.

Mind that Busa di Manna tends to be bulky snowing already after the full moon of September. By then the cableway has already seasonally closed off, but the hiking can last about three hours from San Martino center, provide you’re a decent walker. This article is tagged with Uncertain Oral Tradition, and not without reason.

1. The Secret Night Chant of a Stradivarius Tree ;
2. See also Nuisement and the Sun Resisting Capture , Pietro Perugino and the Lady of the Wind ;
3. Formation of Extreme Cold-Air Pools in Elevated Sinkholes: An Idealized Numerical Process Study pdf , you can find other interesting studies at Cold-Air-Pool Structure and Evolution in a Mountain Basin: Peter Sinks, Utah and Boundary layer evolution within a canyonland basin, numerical simulations of nocturnal flows and heat budges;
4. Bacstrom’s Apparatus to Attract Lunar Humididy and Orthelius Commentary on Sendivogius. Chapter 5 :