BOOK ONE, CHAPTER TWO
Volcanoes and earthquakes could have started as far back as 3.8 billion years ago.
There was a literal seismic shift some 3.8 billion years ago.
Volcanoes have been a natural part of the Earth's landscape for much of its history. Volcanoes are formed when molten rock, or magma, rises to the surface of the Earth and erupts. This magma is made up of molten rock, ash, and gas. When it erupts, it can create various landforms, including lava flows, ash deposits, and cinder cones.
During the prehistoric era, volcanic eruptions played a significant role in shaping the Earth's climate. These eruptions were much more frequent and intense than we experience today.
They released vast amounts of ash, gases, and volcanic aerosols into the atmosphere, triggering remarkable climatic changes. Volcanic eruptions occurred due to the geological activity deep within the Earth's crust.
As magma rose to the surface, it carried dissolved gases such as water vapour, carbon dioxide, sulphur dioxide, and other greenhouse gases. When the eruptions happened, these gases were violently expelled into the atmosphere.
The release of greenhouse gases has a direct impact on the climate. Carbon dioxide, being a potent greenhouse gas, contributes to global warming. Already stated, it resulted in increased temperatures and altered weather patterns. The elevated levels of carbon dioxide also led to acidification of oceans, affecting marine life and coral reefs.
Besides greenhouse gases, volcanic aerosols played a crucial role in prehistoric climatic changes. Volcanic aerosols are tiny particles of ash and sulphur compounds suspended in the atmosphere for extended periods. These particles reflect sunlight into space, causing a cooling effect on the planet's surface. This phenomenon, known as volcanic winter, significantly affected global temperatures.
Volcanic winters lasting months, and sometimes even years, drastically affected the climate. Reduced sunlight and cooler temperatures led to shorter growing seasons and crop failures, impacting humans and animals. Large-scale volcanic eruptions disrupted ecosystems, causing mass extinctions and altering natural habitats.
One of the most significant volcanic eruptions in prehistoric times was the massive eruption of Mount Toba in Sumatra, Indonesia, around 75,000 years ago. This eruption released an enormous volume of ash and gases, leading to several years of volcanic winter. The climate cooled significantly, resulting in a global population bottleneck as many species struggled to survive.
The prehistoric era was characterised by a constant struggle between volcanic activity and its impact on climate. Eruptions caused both short-term and long-term climatic changes, altering landscapes and ecosystems. This dynamic interaction between volcanic eruptions and the climate shaped the course of evolution, influencing the development of life on Earth.
Looking back, we can better understand how volcanic activity and climatic changes were interconnected. While we may not experience the same level of volcanic activity today, it is crucial to recognise the significant influence volcanoes had on shaping our planet's climate and the importance of studying prehistoric climatic changes to comprehend our world better.