Natural materials

Natural materials – clay

In this blogpost we will explore one of the most common natural materials in the world, clay.

What is clay?

Clay is a natural fine-grained material which smoothens out easily under pressure and is often filled with water.

The composition of clay is typically filled with minerals such as kaolinite, etc. these minerals are important for the beauty industry as most common type beauty products utilize some form of clay minerals. Additionally clay minerals are important in certain types of pharmaceutical industries as binders, lubricants, diluents, pigments and opacifiers.

History of clay in pharmacy

The use of clay in the pharmaceutical industry dates back to prehistorian eras where it has been used in pottery for containers of medicine and in 1600 BC a ‘book’ containing evidence that clay was used against hemorrhages and other types of diseases has been found. Underlining the fact that clay is a crucial part of human society for thousands of years.!

Another prehistorian example of clay as a pharmaceutical instrument is In the 400’s BC a book by Hippocrates called “On Airs, Waters and Places”. In this book they describe the Armenian bole and clays usage in healing dysentery and diarrhea. The Armenian bole is a special type of clay often used as medicine, as a pigment and gliding material. It is often red due to the presence of iron oxide.

The important compounds of clay in pharmacy is their mineral composition. In order to characterize clay it usually is subdivided into four main groups corresponding to the mineral content. These are:

  • Kaolinite
  • Smecticte
  • Illite
  • Chlorite

Where further subdivisions can be made of clay based on the mineral plate layering as outlined in Table 1.

S. No.General FormulaGroupLayer Type
3Montmorillonate (Al1.67Mg0.33)
Si4O10(OH)2M + 0.33
Saponite:Mg3(Si3.67Al0.33)O10(OH)2M + 0.33
Palygoskite-sepiolite group
Table 1: Mineral compounds typically found in clay with subdivisions based on typical geometries and mineral composition.

Common use cases of clay

The usages of clay are plentiful and it has been used for various amounts of pottery throughout history. These types of pottery have played an important role when trying to establish a culture and society, as containers have been produced holding everything from water to spices.

In modern history after the industrialization it has been possible to mass produce pottery instead of individual people being employed full time with the occupation suddenly it was possible to free up time for individuals now focusing on something more productive such as innovation and rethinking new technologies.

Related read: Natural Materials – Sand, Common misconceptions of Tsunamis.

Clay pottery as food storage

Meanwhile clay pottery is still used today to store all kinds of inventory such as food, spices and vegetables. With the advent of vegetarianism it might be reasonable to ask: Is clay vegan friendly? And to that the answer is a sounding yes! Clay is absolutely vegan friendly as the compounds making up clay pottery is entirely from non-animal origins meaning that anything vegan that you put in a clay bowl or pottery stays vegan.

Additionally clay pottery is able to withstand high temperatures and doesn’t decompose easily when burnt. Furthermore the trash from clay pottery is entirely natural and thus no need to worry about environmental hazards from trashed clay pottery.

Clay as a building material

Another usage of clays is as a building material for bricks, huts and similar. Here the clay is used to mold bricks in huge ovens allowing for hardening. When hardened and burned, the resulting bricks are capable of withstanding outside weather, rain and storms.

Clay bricks for building have been used for millennia and such the technology of creating bricks from ‘mud’ is something that has withstood the test of time. In a primitive manner, the recipe for creating clay bricks is simple; Mix water, clay, straw and heat until hardened in high temperatures.

Creating bricks with bare hands

An excellent resource for showcasing the simplicity and ancient technology associated with the clay brick creation is the Youtube channel ‘Primitive Technology’. A guy shows in simple steps how to create clay bricks from raw materials.

Video 1: Fired clay bricks as a primitive technology for brick creation

This way of creating bricks is simple yet effective and can be understood through the use of ancient technology.

The flow of liquids through clay

Unlike other materials such as sand, clay has quite an adherence to water. it is hydrophilic in the sense that most clays adsorb water in huge amounts leading to saturated soils. Additionally water passes extremely slowly through clay meaning that it acts as plug stopping all of the water trying to go through.

This property of plugging water and other liquid substances from flowing through clay is important in industries such as oil and gas. In fact clay functions as a lid under which oil and gas collects in huge amounts in large oil reservoirs and often times act as a necessary predisposition for the existence of oil fields.

The drainage of oil wells is a complicated process where high pressures are utilized for pumping water and oil mixtures up towards the surface from deep underground aquifers. Here impermeable layers help build up necessary pressures through overburden stresses allowing the transformation from organic material toward hydrocarbon fossil fuels.

The overburden stressors and impermeable layers can lead to another phenomena called artesian wells.

Artesian wells

An important consideration when trying to identify potential locations for water extraction is the overburden pressures or internal fluid pressures in underground aquifers. These aquifers allow the flow of liquids over large distances and are typically separated by impermeable clay layers. The impermeable clay layers impose stresses on underlying layers resulting in increased internal water pressures. When trying to extract water from such configurations the resulting pressures in the liquid lead to the establishment of artesian wells see Figure 1-2.

An illustration of an artesian well, where the clay\impermeable layer is overlaying the aquifer layers.
Figure 1: Cross-section diagram of an artesian well, USA. Illustration published in Physical Geology by Mytton Maury (University Publishing Company, New York and New Orleans) in 1894. Digitally restored.
Location of the great artesian basin in Australia. The artesian basin is made of aquifers underlying impermeable layers such as clay.
Figure 2:The great artesian basin in Australia consisting of the largest artesian basin in the world spanning more than 1.7 million square kilometers.

The key defining characteristic between regular and artesian wells is the overburden stresses and internal fluid pressures. these allow for the easy extraction of liquids through since flow is automatic up to the surface meaning no need for pumping systems or otherwise extraction techniques.

Water in artesian wells

Artesian wells often contain water. This water is typically of high quality and easily drinkable as the aquifers functions as filtering material of harmful minerals and bacteria. Additionally water from artesian wells are often free from contaminant sources and thus often bottled as spring water more expensive than regular water from taps, examples of such include Fiji water among others.

Oil in artesian wells

In the beginning of the oil era, artesian wells played an important part for extraction of oil. The flowrate is large for aquifers allowing the extraction of huge amounts of oil and the artesian wells didn’t require expensive pumping instruments.

Additionally the locations of the artesian wells made extraction easily manageable as the land deposits at the time were full of oil. An example of such oil fields are displayed in GIF 1.

The land deposits were furthermore located in locations where large infrastructure existed making the pipeline laying easily manageable. This ensured that oil deposits kickstarted the production of oil in the United States within the first years of industrialization.

Clay for sculping

As a last addition clay is also fantastic for sculping sculptures. For the handy people around these sculptures are easily made utilizing a spinning wheel combined with sculpting clays such as monster sculpting clay.

The monster sculpting clay is exceptional for clay sculpting whether you are a beginner just trying it out for the first time or an experienced professional looking for a hard clay based mounding substrate to easily manipulate into beautiful structures or figures.


Mineral composition of clay, source.


Earthquakes – Top ten misconceptions

In this blogpost we explore top ten common misconceptions about earthquakes.

Related read: Top 10 misconceptions about Tsunamis

1. Earthquakes cause violent ruptures of the earth

We all know the scenario from movies, the hero’s try and escape the rupture from the earth. The crack keeps running all the way up to the hero’s foot where it suddenly stops. This common misconception arises since when movies need to be more spectacular.

In fact, earthquakes tremble the earth for up to multiple minutes based on the severity of the earthquake. Earthquakes do not cause earth ruptures as illustrated by an AI below in meme 1.

Thus you shouldn’t be afraid that the earth will split underneath you during an earthquake.

2. It is better to run outside than staying inside during an earthquake

Often times people believe that running outside during an earthquake is safer than staying inside.

By going outside you risk being hit by falling debris, rubble and subduction zones while if you stay inside the building most likely will absorb the earthquake shaking.

It is therefore better to seek shelter inside sheltering yourself from above by hiding underneath tables, beds or sturdy furniture.

This way you are protected by the solidly built walls and ceilings of the building while simultaneously ensuring you are safe from falling books, chest of drawers, fridges, wardrobes and book shelf’s.

3. Earthquakes are predictable events

Unlike most other natural phenomena which we have extensively researched, the predictability of earthquakes still remain a resounding problem in science and engineering.

Top tier researchers still struggle with methodologies and theories to explain and provide early warning systems for earthquakes.

Typically sounding equipment is placed on locations around the globe, allowing the triangulation of epicenters to be calculated.

Related read: How do you calculate an earthquakes epicenter?

4. Earthquakes only happen during warm weather

In ancient greek, they believed that earthquakes were mystical events caused on warm sunny days where the earth opened up underneath their feet and closed again later on, see reference for more information.

Unlike the ancient Greeks, people today have a misconception that earthquakes happen during warm sunny weather.

Although this would be convenient allowing us to better estimate the eminent occurrence of an earthquake, sadly this isn’t the case.

Earthquakes are driven by deep earth dynamics governed by mass and heat transfers indifferent to top-earth weather phenomena.

Thus earthquakes can happen during sunny, rainy, snowy, foggy or stormy weather indifferent to other phenomena’s driving mechanisms.

Related read: Tsunamis the what, when and where

5. The initial shaking is defining a marked ending to the earthquake

A common misconception about earthquakes is that once the initial shaking stops the earthquake is over. This is however not the case. As aftershocks of earthquakes always accompanies the initial shaking and the higher on the Richter scale the earthquake is, the larger and long-lasting the aftershocks become.

Related read: Effective investment strategies for climate adaptations

This means that the danger after the initial shaking recedes unfortunately still resides. The dangerous aftershocks are critical to be vary off, since the initial shaking can loosen and damage buildings while the aftershocks cause weakened structures to collapse or loose debris to fall down on people below.

The Richter scale and aftershocks

The power of the aftershocks and the initial shaking follows a logarithmic scale naturally distributing with powers of 10 in magnitude. This scale, called the ‘Richter scale’ is widely used to describe the severity of experienced earthquakes, see Figure 1 as an example. This scale defines the magnitude of the initial shaking and also defines the aftershocks strengths.

In order to understand the distribution of aftershocks researchers have compared the temporal extent of the number of observed aftershocks with number of days since the main shaking event, see Figure 2. They have found that the distribution of aftershocks with number of shaking events follow an exponentially declining function with time since main shock.

An illustration of the Richter scale with examples of the logarithmic nature of the magnitudes of earthquakes. Examples of historic earthquakes are exemplified
Figure 1: Illustration of the Richter magnitude scale with the logarithmic scale with example earthquakes.
Aftershock duration based on observations and theoretical best fit on days after main earthquake shock
Figure 2: Illustration of the observed aftershocks of the Honshu, March 11´th 2011 Earthquake hitting Japan. The theoretical best fit is shown with a black line.

6. Earthquakes only happen in Japan and USA

Another common misconception about Earthquakes is that they only happen at specific locations around the earth such as Japan and USA.

One of the driving mechanisms behind earthquakes is plate tectonics. Plate tectonics is theoretical framework that is the movement of continents and countries located on drifting (large timescale) plates at different parts of the world.

Plate tectonic

By indexing the world in tectonic sections each within its own plate see Figure 3. It is possible to explain most of the historic movements of continents throughout earth eras and develop theories for the occurrences of earthquakes whose likelihood depends on the locations of fault-lines of the different types such as subduction, lateral sliding and spreading.

Illustration of the plate tectonics of the earth with naming and three different types of fault line zones illustrated.
Figure 3: Tectonic Plates world map vector diagram and tectonic movement illustrations showing subduction, lateral sliding and spreading process.

The Western Mediterranean – a new example

As a newer example lets take a closer look at the interesting fault-lines which are the located at the Western Mediterranean towards the Gibraltar strait. This area is interesting because of the differences within the topographic and bathymetric features clearly shown in Figure 4.

Figure 4 and 5 include locations and markings of fault-lines together with recorded magnitude earthquakes. Arrows show the measured movement of the tectonic plates given as a yearly movement in mm’s. Corresponding to roughly 4.5 mm’s per year for the North African continental crust.

Scientific explanation of the development of a possible new fault-line within the Wester Mediterranean sea. Location of earthquakes with magnitudes, zoomed in area of interest and fault-lines are marked along bathymetric features, topographic terrain and movement arrows.
Figure 4: Reproduced from Figure shows the magnitude earthquakes, strike-slip fault-lines, normal fault lines and the proposed development of a new tectonic plate located near the end of the western Mediterranean sea.
Zoom in of the Wester Mediterranean. fault-lines and figure markings with other zoomed in areas are shown.
Figure 5: Reproduced from Closeup of the investigated area encircled with a white rectangular box. The given fault-lines are shown accordingly.

7. Drills can negate earthquake damages

To battle the damages of earthquakes we incorporate drills that explain to children that they should run for cover and hide underneath tables. This way of providing false hope to children can be dangerous if not correctly addressed.

Knowing when to run outside and when to seek cover inside is important as a means of preventing human injury during an earthquake. The damaging forces from earthquakes are not influenced by people running away from them.

In order to mitigate the damaging effects of earthquakes it is therefore necessary to continuously invest sturdier building materials, equipment and tuned mass dampers for high-risers. Such that buildings resistance towards the damaging shaking of earthquakes are continuously improving.

Preemptive investments are key to ensure that future disastrous events are accounted for and mitigated as much as possible.

Related read: Effective climate adaptation strategies

The drills are an important supplement which allow people to react quickly in the event of an earthquake. This must be accompanied by smart investment decisions enhancing the existing building mass for everyone benefit.

8. Building codes == safe buildings

Strict building codes lead to safer buildings. This is a common misconception present across the globe.

In fact, the foundation for safe buildings is strict building codes mixed with the efficient quality assurance. High-quality building work with proper quality control, safe building environments and senior-staff controlling junior is key.

The senior staff must check work carried out by junior laborer, allowing for the detection of faults and errors early on in the building process. The early detection of errors is critical for ensuring high-quality work and consequently safe buildings according to the strict building codes.

9. The implications of earthquakes are local

The effects of earthquakes can cause other dangerous events such as Tsunamis. Implications of earthquakes and the resulting consequences of their generated Tsunamis are dangerous and possibly globally covered.

The Tsunamis can spread from epicenters across the globe causing massive damages all because of earthquakes are displacing large amounts of water.

The damages on energy infrastructure such as nuclear powerplants can potentially damage the environment of the entire globe. These powerplants are vulnerable to earthquakes happening in the vicinity. History tells us that nuclear waste as a result of earthquake disasters can spread across the globe and pose a real threat for the environment and the people living in it.

10. Earthquakes are all the same

A common misconception about earthquakes is that all of them are the same in the fact that they are developing similarly across the globe regardless of the fault line types.

This is incorrect since earthquakes are dynamic phenomena whose development depend on the different instances of the boundary conditions as well as the soils initial state before the shaking starts.

The marginal effects of earthquakes are essentially changing with the initial state of the soil, plate tectonics and recent geological activity. These effects are difficult if not impossible to accurate describe throughout the three-dimensional medium.

Geophysical surveys make it easier to try and estimate tectonic plate composition. The survey depths of intrusion are however sufficiently deep to fully explain the plate tectonic behavior.

Bonus: Earthquakes can change the length of a day

In fact earthquakes are not only powerful destructive events, they can actually (in theory) change the length of a day on earth.

By releasing an increasing amount of energy through the shaking events, it is possible for the most powerful earthquakes to change earths rotation and thus the length of a day.


Gómez de la Peña, L., R. Ranero, C., Gràcia, E. et al. Evidence for a developing plate boundary in the western Mediterranean. Nat Commun 13, 4786 (2022). Used under creative commons license 4: