A Geologist Explains Why Soil Cracks Form Each Summer

[@taimalik1110]

Professor Day, you're an excellent teacher!

[@EarthandSpaceSciencesX]

Wow, thanks!

[@deepquake9]

Very interesting video. Thank you.

[@EarthandSpaceSciencesX]

Thank you too!

[@miklov]

Fascinating. That the road tends to crack at the fringes, could that also be due to the road surface preventing evaporation from the ground, sealing moisture under it? I imagine that moisture doesn't propagate nearly as well under asphalt as it does in open cracks.

[@EarthandSpaceSciencesX]

Absolutely true (and I toyed with discussing that but didn’t want the video to be too long). The water has trouble infiltrating and evaporating through the asphalt so the soil is less affected near the middle..unless a crack forms there then all bets are off.

[@b_uppy]

They do get soil subsidence in SoCal. It has everything to do with soil biota. You need to study soil biomes. The Midwest has very few trees where savannas are natural. If the savannas are restored the subsidence will reduce. Happily trees are encroaching from the East. Knowing more about soil biomes will give you your answers.

[@b_uppy]

[Addendum] Carbon-rich topsoil assisted by healthy, diverse soil biota, polycultures of biome-appropriate trees, vines, shrubs, and perennials, avoiding bare ground, synthetic inputs, year round regreening, etc also reduces cracking. We can regreen and produce food at the same time. This includes livestock as part of the management system. It is vastly more efficient to manage land and produce food using soil restorative methods. It relocalizes food security while also increasing market diversity. Farmers wishing to switch would need to form cooperatives to get peak efficiency and reach larger markets.

[@michaelsanfilippo7433]

Very interesting and clear explanation. I enjoy all of your videos, wish you could do more. Being from Southern California, it would be great if you could do a series of field studies on So Cal.

[@EarthandSpaceSciencesX]

I am considering doing a entire series on California geology, so doing something like that would be right up my alley. It was one of my favorite graduate school topics and I know all the good spots! Unfortunately, my current academic appointment has me in Texas, so I’m not in California as often as I’d like to be.

[@arielrodriguez6980]

In my lawn in the Texas heat I get a crack pattern like octagons/squares on the soil. Does this mean it is too dry only on the surface area or it is dry even deeper?

[@EarthandSpaceSciencesX]

As the cracks grow, the soil will dry out deeper down, so it could damage the roots for trees if the drought gets too severe. This video was filmed in north Texas. :)

[@arielrodriguez6980]

@@EarthandSpaceSciencesX Basically I need to water to the point where there aren't any visible soil cracks, yes?

[@EarthandSpaceSciencesX]

@@arielrodriguez6980 well, the soil may not allow that to happen, but you can try. The best you can do is to try and keep the cracks from growing by making sure water gets down into them.

[@providencebullykennels2504]

Will filling the soil cracks with more soil help?

[@EarthandSpaceSciencesX]

Only for that summer. The next summer the cracks will return. Watering is the key.

[@MasterMalrubius]

Always love seeing a new video from you.

[@providencebullykennels2504]

I have huge soil cracks in my backyard. Will it take lots and lots of water to embd those cracks?

[@EarthandSpaceSciencesX]

Depends on the soil, but keeping the ground watered normally will usually close or restrict the growth of all the cracks.

[@JCtheMusicMan_]

I lived in Oklahoma for 10 years and had a house where my uphill neighbors gutter runoff went directly under my house and the home inspector recommended I dig a french drain. I eventually needed to rent a jack to shim the piers to prevent cracks. Excellent lesson as always professor!

[@johnlord8337]

So, this explains much, as having peeps in SoCal and (just today) they mention their clay and granite sands - and no cracks - but when the rains come there is no absorption and instant runoff with flash floodings down the slopes. While we in SanFran Bay have something akin to caliche, the most obnoxious clayish soil (makes stucco and adobe look like playdo, with no NKP, yet because of its alkali minerals (calcium, magnesium, etc) it grows all kinds of weird plants with irregular shapes but has productive fruiting on "nothing soil" - and yet no cracking here. What we do have, otherwise, when it truly rains, eventually our overburdened wet topsoil (layer O and A) atop a hardened and dry soil layer B, C, and bedrock ... and we see cracking happening with landslippage as seen in East Bay Parks Coyote Hills, a little caliche island in the swamplands near Fremont, ... and the hills of Niles (with the most stable of all Fremont area geological strata ! - with these recent rains also started showing cracks on the slopes. My mentions to others in those areas ... watch out for a substantial landslide of such devastating subsidence, taking out housing and commuter roadways, if we get another portion of last year's seasonal rains again.

[@RobertRodgers-r5h]

Thank you!

[@deepquake9]

Hey professor Dave!

[@EarthandSpaceSciencesX]

Professor Day* :)

[@HT-io1eg]

Great tutorial. I studied Geography (geology, geomorphology, human, economic, climatology) to age 18 and to this day I wish I’d taken it at university. Humans in their natural environment is the widest of subjects

[@22terrytibbs]

Got some land shifting there too? Can see some serious slanting in those background trees and some fence posts.