Hall 6 - The Earth – a dynamic Planet
In hall 6 - the geology hall - the relationship between the lithospere (the Earth's crust and the upper part of the mantle) and the biosphere
(which includes all living things on earth) is highlighted.
The exhibition spans from the structure of the earth to the Anthropocene - the age in which humans began to emerge as a geological
force. Interactive stations allow visitors to experience changes in the earth up to the present day and show how life became
possible.
The Balmhorn Mountains in Switzerland were created when former marine sediments were pushed up against each other to create
gigantic folds
Anyone who associates geology only with boring rocks will be surprised by the new exhibition at the NHM Vienna, which is equipped
with many hands-on objects and demonstrates how comprehensively the earth sciences are trying to decipher the processes of
our planet today. The boundaries between scientific disciplines have long been blurred, and from rocks the path quickly leads
to the atmosphere and hydrosphere or to the world of microbes.
The exhibition focuses on little-known geological deposits in the oceans, such as methane ice and manganese nodules, which
are formed by microorganisms. As sources of energy and raw materials, they could meet the needs of industry for decades to
come. At the same time, they are tied to fragile ecosystems that will be lost forever if mined. The enormous dimensions of
these submarine deposits, which cover an area the size of Europe, are illustrated by spectacular video footage from diving
trips by GEOMAR and the Ocean Exploration Trust.
The exhibition also shows the danger posed by methane ice as a climate killer, using examples from the geological past. The melting of methane ice 55 million years ago was followed by a climatic catastrophe with high temperatures and great drought, which led to the dwarfing of the animal kingdom. A similar event 8,000 years ago triggered a tsunami, whose 20-meter-high tidal wave devastated the coasts of northern Europe. In terms of warming oceans, melting methane ice deposits are a very real threat to us and our already battered
climate system.
The exhibition also shows the danger posed by methane ice as a climate killer, using examples from the geological past. The melting of methane ice 55 million years ago was followed by a climatic catastrophe with high temperatures and great drought, which led to the dwarfing of the animal kingdom. A similar event 8,000 years ago triggered a tsunami, whose 20-meter-high tidal wave devastated the coasts of northern Europe. In terms of warming oceans, melting methane ice deposits are a very real threat to us and our already battered
climate system.
Another unusual theme of the exhibition is the rhythms that shape our planet. Life on Earth is determined by the movements between the Sun, Earth, and Moon. Cycles such as day and night, the phases of the moon and the seasons determine the course of life and are directly perceptible to plants, animals, and humans. In an audiovisual installation, the exhibition makes it possible to experience these rhythms as “world music” in an unusual way.
The spheres of planet Earth
Lithosphere, hydrosphere, atmosphere, and biosphere – the interaction of these four spheres makes the Earth unique. The lithosphere
is the solid rock shell, the hydrosphere and cryosphere contain water in liquid and frozen form, the atmosphere is the shell
of air, and the biosphere comprises all life. All spheres are interacting with each other all the time – without this, life
would not be possible.
Fact sheet
- The lithosphere is the size of a ball with a diameter of 4,000 km.
- The atmosphere is the size of a ball with a diameter of 2,000 km.
- All the water on Earth would fit into a ball with a diameter of 1,400 km.
- The entire biosphere is the size of a ball with a diameter of just 15 km.
The spheres of planet Earth
Earth was formed 4.54 billion years ago. As the planet gradually cooled, the outermost layer of the Earth – the early lithosphere
– became solid 4.4 billion years ago. Around the same time the hydrosphere developed in the form of the first oceans. The
first atmosphere, albeit one without oxygen, was also created during the Earth’s early phase. The biosphere began to develop
3.8 billion years ago with bacteria-like single-cell organisms. Tectonic plate activity began 4 billion years ago and still
maintains the interaction between the spheres until this day.
Fragile as stone
The solid surface of the Earth is the lithosphere. It consists of seven large plates and numerous small plates. These plates
float on the asthenosphere, a partially melted section of the Earth’s mantle. Differing rock densities and varying temperatures
lead to activity in the Earth’s mantle, which in turn drives the movement of the tectonic plates. This process can cause the
plates to shift by up to 15 cm a year. Tectonic plate activity keeps the solid, uppermost layer of the Earth in motion. It
can generate huge forces, especially at the edges of the plates. The deeper you go, the higher the temperature and pressure
become. Rocks react to these increases and are transformed. Tectonic plates pushing against each other form fold mountains
but also create fault zones, where sections of rock break apart and are pressed up against each other.
Rock fold in granulite (Krug, Lower Austria). The rock was deformed 340 million years ago at 1000°C at a depth of 60 km. On
loan: University of Vienna, Institute of Geology.
Engine of life
Without tectonic plate activity there would be no life. The movement of the tectonic plates releases carbon dioxide, stored
within dead organisms in sediments, into the Earth’s mantle. Millions of years later this greenhouse gas is returned into
the atmosphere by volcanoes – and forms the basis of life for the plants and plankton which depend on photosynthesis. Without
this replenishment process the carbon dioxide in the atmosphere would be completely used up within a million years.
Plate tectonics animation. © Florian Doppel-Prix
The lithosphere cycle
Tectonic plate activity keeps the material of the lithosphere in a constant cycle. When a plate breaks, this causes trenches
– a good modern-day example is the East African Rift Valley. If the plates then move further apart, magma rises along the
edges of the tectonic plates. This creates mid-ocean ridges with young, volcanic rocks and wide-open ocean basins such as
those found in the Atlantic. Finally, the denser oceanic crust is pushed under the continental crust at the edges – a phenomenon
which can be seen in the Pacific today. During this process the oceanic crust is completely recycled. This cycle takes about
180 million years, so there are no ocean floors which are older than this.
Rock cycle
The structure of the Earth
We cannot look inside the Earth’s mantle or core. Even when it comes to the Earth’s crust, the deepest boreholes have penetrated
no more than 12 kilometers. Our knowledge of the inner structure of the Earth comes from studying how earthquake waves spread.
Iron meteorites also provide valuable information, as they are believed to be similar to the Earth’s core.
The Earth's crust
Oceanic and continental crust form the uppermost parts of the Earth’s surface. The oceanic crust, which is about 5 to 10 kilometers thick, consists mainly of magmatic rocks, such as gabbro and volcanic basalt. The continental crust, which is 30 to 60 kilometers thick, is mainly made up of rocks with a high quartz content, such as granite and the volcanic rock rhyolite.
Oceanic and continental crust form the uppermost parts of the Earth’s surface. The oceanic crust, which is about 5 to 10 kilometers thick, consists mainly of magmatic rocks, such as gabbro and volcanic basalt. The continental crust, which is 30 to 60 kilometers thick, is mainly made up of rocks with a high quartz content, such as granite and the volcanic rock rhyolite.
Volcanic rock: rhyolite (Sarentino, South Tyrol, Italy) 280 million years old.
The Earth's mantle
The Earth’s mantle is solid but malleable. It extends from the Earth’s crust to the Earth’s core at a depth of 2,900 km. Temperatures inside the mantle can reach up to 3,500 °C as you approach the Earth’s core. Typical mantle rocks are peridotite and eclogite. The Earth’s mantle is in constant motion. Hot material from near the Earth’s core slowly moves upwards, while cooler and denser rock from the upper region sinks downwards. This slow circular process takes many millions of years. Close to the Earth’s crust the rock can melt because the pressure is lower. New magmatic rocks are formed or come to the surface through volcanoes.
The Earth’s mantle is solid but malleable. It extends from the Earth’s crust to the Earth’s core at a depth of 2,900 km. Temperatures inside the mantle can reach up to 3,500 °C as you approach the Earth’s core. Typical mantle rocks are peridotite and eclogite. The Earth’s mantle is in constant motion. Hot material from near the Earth’s core slowly moves upwards, while cooler and denser rock from the upper region sinks downwards. This slow circular process takes many millions of years. Close to the Earth’s crust the rock can melt because the pressure is lower. New magmatic rocks are formed or come to the surface through volcanoes.
Mantel plumes in the Earth's mantle
The Earth's core
Underneath the Earth’s mantle is the Earth’s core, which has a diameter of 7,000 km. The Earth’s core consists of iron and
nickel. The inner core reaches temperatures of up to 5,000 °C and is solid because of the high pressure. The outer core is
liquid. This liquid area, together with the rotation of the Earth, is responsible for Earth’s magnetic field. For 4 billion
years this magnetic field has protected the Earth from hard UV radiation. Without it there would have been no life on land.
Gibeon iron meteorite with Widmannstätten pattern (Namaqualand region, Namibia), 4.56 billion years old (width: 50 cm). Originates
from the metal core of a minor planet. The inner core of the Earth is believed to contain similar structures
Geological revolutions of life
As soon as life had formed, it began changing its environment. Even the rocks were changed by life itself. Two major events
were decisive in this process: the invention of photosynthesis and the development of soil.
The colors of the Earth
Life originated about 3.8 billion years ago. One of its most important “inventions” is photosynthesis. This phenomenon, which developed around 3.4 billion years ago, enables plants and plankton to absorb carbon dioxide from the atmosphere and release oxygen as a “waste product”. Finally, 2.4 billion years ago, so much oxygen had accumulated in the atmosphere that the Earth began to “rust”. This event is known as the Great Oxidation Event. Newly formed minerals changed the appearance of the Earth forever. Without oxygen we would have neither the brown of the soil nor the yellow of the desert.
Sea coast with stromatolites more than 2 billion years ago. Methane colored the early oxygen atmosphere pink. The Moon was
closer to the Earth than it is today.
Unique in the solar system: soil
At the interface between the lithosphere and the atmosphere, life itself has created a unique habitat: the soil. Soil formation began only 470 million years ago when plants spread onto the mainland. The principle remains the same today and is based on the symbiosis between fungi and the roots of plants. The fungi dissolve nutrients from the rock and pass them on to the plants. The plants “feed” the fungi with sugar. This symbiosis led to a completely new form of weathering, resulting in enormous amounts of nutrients becoming available to life.
At the interface between the lithosphere and the atmosphere, life itself has created a unique habitat: the soil. Soil formation began only 470 million years ago when plants spread onto the mainland. The principle remains the same today and is based on the symbiosis between fungi and the roots of plants. The fungi dissolve nutrients from the rock and pass them on to the plants. The plants “feed” the fungi with sugar. This symbiosis led to a completely new form of weathering, resulting in enormous amounts of nutrients becoming available to life.
Mycorrhiza: The symbiosis between roots and fungi is one of the most important symbioses in the world
Written in stone
Every rock has its own story. You can read it by taking a close look at its component parts, the minerals. The composition
and shape, size, and arrangement of the minerals reveal the conditions under which a rock was formed. But no stone lasts forever
– weathering and tectonic plate activity create new rocks.
Under pressure - metamorhpic rocks
The formation of mountains and tectonic plate activity pulls rocks down into the Earth’s crust, where they are transformed. Depending on the pressure and temperature, their structure changes and new minerals are generated. This “fingerprint” makes it possible to calculate at which depth a rock was formed. Under pressure, granite or even sandstone can be turned into gneiss. Former coral reefs become marble, and volcanic basalt is transformed into amphibolite.
The formation of mountains and tectonic plate activity pulls rocks down into the Earth’s crust, where they are transformed. Depending on the pressure and temperature, their structure changes and new minerals are generated. This “fingerprint” makes it possible to calculate at which depth a rock was formed. Under pressure, granite or even sandstone can be turned into gneiss. Former coral reefs become marble, and volcanic basalt is transformed into amphibolite.
Marble (bright) with layers of amphibolite (dark); Atzelsdorf, Lower Austria. Formed 340 milion years ago at a depth of up
to 30 km at ca. 750 °C
Messenger from the deep - magmatic rocks
As magma rises, it cools and solidifies. The slower it cools, the more time the crystals have to grow. One after the other,
different types of minerals crystallize; large crystals can form. These igneous rocks from the Earth’s mantle and crust only
come to the surface through tectonic plate activity. If magma rises fast, there is no time for cooling. The resulting volcanic
rocks solidify quickly when they reach the Earth’s surface and consist of small crystals.
Weinsberg Granite Ardagger Markt, Lower Austria Formed 345 million years ago at a depth of up to 25 km at up to 700 °C.
Built on sand - sediments
sand, and gravel – are formed by the weathering of rocks. Just a few kilometers thick, they represent merely the thin skin of the lithosphere. They can contain remains of living organisms and are therefore important carbon dioxide reservoirs. Living organisms themselves can also form sediments. There are whole mountains made up entirely of shells from unicellular organisms such as calcareous foraminifera, calcareous nannoplankton, or siliceous shells of diatoms.
sand, and gravel – are formed by the weathering of rocks. Just a few kilometers thick, they represent merely the thin skin of the lithosphere. They can contain remains of living organisms and are therefore important carbon dioxide reservoirs. Living organisms themselves can also form sediments. There are whole mountains made up entirely of shells from unicellular organisms such as calcareous foraminifera, calcareous nannoplankton, or siliceous shells of diatoms.
Petrified mud with wave ripples of an intertidal coast Dubová Hora, Czech Republic; Cambrian, 510 million years old.
It could have turned out quite differently
Not all revolutions of life were successful. The development of life was far from linear. The earliest multi-celled organisms
appeared 2.1 million years ago. These Gabonionta were first identified in Gabon, West Africa. Their
different shapes suggest different ways of life. These unique fossils are currently only on display at the Natural History Museum Vienna. They were several centimeters in size but soon died out due to a sharp drop in oxygen levels in the atmosphere. Without this disaster, life would have developed in a completely different way. It was not until a billion years later that multi-celled organisms emerged once again.
different shapes suggest different ways of life. These unique fossils are currently only on display at the Natural History Museum Vienna. They were several centimeters in size but soon died out due to a sharp drop in oxygen levels in the atmosphere. Without this disaster, life would have developed in a completely different way. It was not until a billion years later that multi-celled organisms emerged once again.
Original of one of several types of Gabonionta. Franceville, Gabon, West Africa; 2.1 billion years old; Loan by Abderrazak
El Albani | Université de Poitiers, Poitiers, France.
Alternative worlds
The Industrial Design class at the University of Applied Arts Vienna carried out a project investigating what the world might look like if the Gabonionta had evolved. These fictional scenarios do not claim to be scientifically accurate, but are instead intended to illustrate the infinite variety of paths that were open to life ... and perhaps still remain open?
The Industrial Design class at the University of Applied Arts Vienna carried out a project investigating what the world might look like if the Gabonionta had evolved. These fictional scenarios do not claim to be scientifically accurate, but are instead intended to illustrate the infinite variety of paths that were open to life ... and perhaps still remain open?
© Film by Anna Maria Sudy, Lisa Sperber, Rosa Sturm and Markus Pettrém.
Life as a geological force
Limestone, coal, and oil are formed by living organisms. They bind carbon from the atmosphere and store it in the lithosphere
for millions of years. The most important coal deposits date from the Carboniferous period and are over 300 million years
old. Since then they have stored carbon dioxide extracted from the atmosphere by tropical rainforests at that time. Oil and
gas, on the other hand, were formed mainly from microscopic marine organisms such as algae. Besides oil and gas there are
two further, albeit relatively unknown, raw materials
formed by microorganisms: methane ice and manganese nodules. Due to the changing CO2 concentration in the atmosphere, the temperature also was subject to large fluctuations. Particularly warm phases of Earth’s history were the Early Triassic and the Late Cretaceous. Ice ages occurred during the Ordovician and at the turn from Carboniferous to Permian.
formed by microorganisms: methane ice and manganese nodules. Due to the changing CO2 concentration in the atmosphere, the temperature also was subject to large fluctuations. Particularly warm phases of Earth’s history were the Early Triassic and the Late Cretaceous. Ice ages occurred during the Ordovician and at the turn from Carboniferous to Permian.
Methane – a sleeping giant
Gas hydrates are far more important than coal, oil, and natural gas as carbon reservoirs. They occur in enormous quantities frozen into ice on the continental slopes of the oceans and in permafrost areas. Gas hydrates are formed by single-celled microorganisms known as archaea. Their main component is methane,
which can be extracted as a fossil fuel. During this extraction process the continental slopes are literally ploughed up, causing massive destruction of habitats. Current global warming could cause the methane to melt completely, thereby triggering a global climate catastrophe.
Gas hydrates are far more important than coal, oil, and natural gas as carbon reservoirs. They occur in enormous quantities frozen into ice on the continental slopes of the oceans and in permafrost areas. Gas hydrates are formed by single-celled microorganisms known as archaea. Their main component is methane,
which can be extracted as a fossil fuel. During this extraction process the continental slopes are literally ploughed up, causing massive destruction of habitats. Current global warming could cause the methane to melt completely, thereby triggering a global climate catastrophe.
Methane ice in marine mud, cross section of the uppermost sediment layers (model).
Manganese nodules – a habitat under threat
Manganese nodules are formed by iron bacteria on the ocean floor at a depth of over 4,000 meters. They cover a huge area in the Pacific – equivalent to half the size of Europe. Apart from manganese, the nodules contain high levels of nickel, cobalt, tellurium, and copper – important raw materials for computers, mobile phones, and car batteries. Manganese nodules grow just a few millimeters in a million years. Mining them using trawl nets destroys this deep-sea habitat forever.
Manganese nodules are formed by iron bacteria on the ocean floor at a depth of over 4,000 meters. They cover a huge area in the Pacific – equivalent to half the size of Europe. Apart from manganese, the nodules contain high levels of nickel, cobalt, tellurium, and copper – important raw materials for computers, mobile phones, and car batteries. Manganese nodules grow just a few millimeters in a million years. Mining them using trawl nets destroys this deep-sea habitat forever.
Geological danger from the depths
Fifty-six million years ago, the climate suddenly warmed. The methane ice frozen in the continental slopes began to melt,
releasing large quantities of methane into the atmosphere within a short time. In the time span of just 5,000 years the temperature
rose by 8 °C! Even in Siberia the seawater was 27 °C. This change had a major impact on plants and animals – they adapted
to the hot, dry climate by becoming smaller. This phenomenon of “dwarfing” occurred in many animal groups, from worms to primitive
horses to early carnivores.
It took about 200,000 years for the methane to be broken down and the climate to stabilize.
It took about 200,000 years for the methane to be broken down and the climate to stabilize.
Dwarfed mammal – Diacodexis, an early cloven-hoofed animal (55 million years old)
The Storegga landslide
Approximately 8,200 years ago, the methane ice off the coasts of Norway began to melt. This resulted in a huge debris avalanche which cascaded into the water, creating a tidal wave up to 20 meters in height. If today’s gas hydrates were to melt, this would also trigger tsunamis.
Approximately 8,200 years ago, the methane ice off the coasts of Norway began to melt. This resulted in a huge debris avalanche which cascaded into the water, creating a tidal wave up to 20 meters in height. If today’s gas hydrates were to melt, this would also trigger tsunamis.
The Storegga landslide in the North Atlantic. Red circles indicate traces of the tsunami wave on the coasts of Northern Europe,
which are still visible today
Rocks as climate archives
Climate controls weathering and thus also the creation of sediment deposits. Sedimentary rocks are therefore good climate
archives. Their chemical and physical properties as well as the fossils they contain indicate cold or warm periods and make
it possible to draw conclusions about nutrients and precipitation. Examining long sequences of sedimentary rocks allows us
to reconstruct the development of the climate on Earth over millions of years. Drill cores from the ocean or from deep lakes
are particularly good climate archives. International scientific institutions such as ECORD and ICDP take cores for research
projects on the Earth’s climate history. Some of the greatest catastrophes and upheavals in Earth’s history can only be reconstructed
in detail using such climate archives.
The "fever curve" of the Earth
The variation of temperature during the last 65 million years was reconstructed with the help of drill cores. The Eocene was
a period characterized by a very warm climate, significantly warmer than today. It was not until 35 million years ago that
the Earth cooled down and ice sheets formed at the South Pole. In the Late Pliocene, about 3.6 million years ago, glaciers
began to form at the North Pole. The Quaternary was then characterized by ice age cycles that continue to this day. The formation
of mountains and changes in global ocean currents due to tectonic activity were important triggers for changes in the climate
system.
"Fever curve" of the Earth during the last 66 million years: The red and blue shades show the deviation from the temperature
of the period 1961 to today
Man as geological force
Humans have been changing their environment for thousands of years. Humankind itself has become a geological force. The geological
age of human beings is the Anthropocene, derived from the Greek word “anthropos” meaning human.
Steel, concrete, and plastic Since 2020, the amount of material created by humans has exceeded the total amount of biomass on Earth! Long after mankind has become extinct there will still be mighty deposits of steel, concrete, and plastic covering large parts of the planet. Traces of the Anthropocene can be found all the way down to the depths of the oceans in the form of heavy metals and microplastics. The warming of the atmosphere through greenhouse gases and the acidification of the oceans are also features of the Anthropocene.
Steel, concrete, and plastic Since 2020, the amount of material created by humans has exceeded the total amount of biomass on Earth! Long after mankind has become extinct there will still be mighty deposits of steel, concrete, and plastic covering large parts of the planet. Traces of the Anthropocene can be found all the way down to the depths of the oceans in the form of heavy metals and microplastics. The warming of the atmosphere through greenhouse gases and the acidification of the oceans are also features of the Anthropocene.
Climate development of the Earth during the last 600 million years
The beginning of the Anthropocene
The beginning of each geological epoch is defined by a global event, such as the first appearance of a living being. Which event should define the start of the Anthropocene is a subject of debate among researchers. The event should be one which is still detectable in sediments worldwide millions of years from now. The first appearance of Homo sapiens 300,000 years ago is therefore not a suitable starting point. One possibility would be the first atomic bomb test in 1945. The radioactive fallout that followed this and the further 2,100 or so explosions can be detected worldwide – and still will be in millions of years’ time.
The beginning of each geological epoch is defined by a global event, such as the first appearance of a living being. Which event should define the start of the Anthropocene is a subject of debate among researchers. The event should be one which is still detectable in sediments worldwide millions of years from now. The first appearance of Homo sapiens 300,000 years ago is therefore not a suitable starting point. One possibility would be the first atomic bomb test in 1945. The radioactive fallout that followed this and the further 2,100 or so explosions can be detected worldwide – and still will be in millions of years’ time.
View of Hong Kong – megacities as symbols of the Anthropocene?
“Climax” nuclear bomb test in Nevada on June 4, 1953.
History of the "Emperor's Hall"
Hall 6 is the oldest furnished room in the Natural History Museum. It is still known today as the “Kaisersaal” or “Emperor’s Hall”. There are two reasons for this nickname. Firstly, it originally housed the “Kaiserbild”, a painting of Emperor Francis I now on display by the staircase. Secondly, the hall’s decorative style is dominated by the building’s patron, Emperor Franz Joseph I.
Hall 6 is the oldest furnished room in the Natural History Museum. It is still known today as the “Kaisersaal” or “Emperor’s Hall”. There are two reasons for this nickname. Firstly, it originally housed the “Kaiserbild”, a painting of Emperor Francis I now on display by the staircase. Secondly, the hall’s decorative style is dominated by the building’s patron, Emperor Franz Joseph I.
The ship “Admiral Tegetthoff” in pack ice.
Six of the seven oil paintings show places named after the Emperor:
- "Emperor Franz Josef Fjord, East Coast of Greenland” by Albert Zimmermann (1809–1888)
- "Emperor Franz Josef Land, The Abandoned Tegetthoff” by Julius von Payer (1841–1915)
- "Emperor Franz Josef Glacier New Zealand” by Adolph Obermüllner (1833–1898)
- "Franz Josefhöhe with the Pasterze Glacier” by Eduard Peithner von Lichtenfels
(1833–1913) - "Cap Tyrol, Emperor Franz Josef Land” by Julius von Payer (1841–1915)
- "Austria Sound”, a night scene of Emperor Franz Josef Land, by Julius von Payer (1841–1915)
The painting “Der Austria Sund” was lost and has been replaced by a modern work by the painter Franz Messner (2006). The painting “From Dalmatia” is the only image that does not make a reference to the emperor. It was produced by Lea von Littrow – the only female painter involved in the decoration of the museum. She worked under the pseudonym Leo Littrow.
As with all the corner halls on the mezzanine floor, Hall 6 also has a number of sculptures. These were created by Edmund Hofmann von Aspernburg (1847–1930).
Four pairs of figures represent the Four Elements which have been a constant since ancient times: earth, water, fire, and air. The other figures show several chemical elements (gold, silver, iron, copper, arsenic, lead, tin, and mercury) that were important as raw materials.
Allegorical representation of the "element" air
