When you look at the vast, arid landscape of the Sahara desert, you may find it hard to believe that this was once a lush, green space full of grasses, trees and lakes. Yet this is likely the case. It has been called the North African Humid Period, and occurred around 12,000 years ago during the late Pleistocene and Holocene geological epochs.
There is good paleoclimatological evidence to suggest that over the last 3,000,000 years, there have been 230 of these North African Humid Periods (NAHPs), indicating that the Sahara region alternates between arid phases (as present) and humid phases, which are full of rivers, vegetation and lakes. According to an article in Nature Magazine online, these NAHPs are governed by a phenomenon known as the Procession Cycle, which is when a wobble occurs in the orientation of the Earth’s axis of rotation. Thereafter, you might imagine the planet as a slightly off-centre spinning top. This off-centre rotation continues for a period of around 25,000 years. Procession is an additional form of planetary motion to the more well-known daily rotation and annual revolution cycle of the Earth. It is caused by the gravitational tidal force of the Sun and Moon acting on our planet’s equatorial bulge. There is a good visual of this rotational phenomenon here on Wikipedia.
The wobble itself is known as an Axial Procession, and it makes seasonal contrasts more extreme in one hemisphere and less extreme in the other. Not only does the procession cycle govern the seasonal contrasts, it determines temperature and precipitation variance between seasons. During the periods of increased Boreal Summer Insolation (when solar radiation hits the Earth’s northern hemisphere between March and September), the African Monsoon systems are intensified. It is these precipitation-rich phases of the procession cycle that underpin the North African Humid Periods.
This article in the Geographical explains how the most recent incarnation of the dry version of the Sahara came about. Around 12,000 years ago, the end of the ice age led to a wetter climate in the region, possibly due to low-pressure areas forming over collapsing ice-sheets in the north. But, once these ice sheets melted, the Northern Sahara region dried out. However, monsoon conditions in the South meant that the Southern Sahara region was wetter. But, eventually this monsoon retreated south (as part of the procession cycle) and the entire Sahara region become desert. This is the incarnation of the Sahara you see today.
When will this cycle end, then? Well, not for a while. Experts predict that the Sahara will revert back to that lush green alternative state in about 10,000 years.
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Our planet is a treasure trove of fascinating natural wonders, and when it comes to geographical oddities, few things are as intriguing as islands within lakes within islands. These peculiar formations defy conventional expectations, showcasing the awe-inspiring creativity of nature. Today, we embark on a journey through this quirky world.
One remarkable example of this phenomenon can be found in the heart of Canada’s Manitoulin Island, the largest freshwater island in the world. Within the already impressive Manitoulin Island lies Lake Manitou, a vast inland lake that holds an astonishing secret. Deep within the waters of Lake Manitou are two smaller islands: Treasure Island and Flowerpot Island. These each create a mesmerising and unexpected natural spectacle, demonstrating nature’s ability to surprise and astonish us.
Venturing across the globe, we find another illustration of this phenomenon in the Philippines. In the picturesque Taal Lake, or Taal Volcano Caldera (pictured), rests Volcano Island. This island, shaped like a smaller replica of its titular parent volcano, holds its own miniature crater lake, known as the Main Crater Lake. Intriguingly, it temporarily vanished following the eruption of the Taal volcano in 2020, but as the eruption subsided and very wet weather blew in, it returned. This shows how the interplay of such inter-related geographic features creates truly unique, as well as visually stunning landscapes.
These geographical oddities not only captivate our imagination but also serve as valuable reminders of the dynamic forces that shape our planet. They are windows into the geological history of an area, revealing a complex interplay of volcanic activity, erosion, and tectonic forces. By studying these formations, scientists gain insights into the intricate processes that have shaped our world over millions of years. We are reminded that the natural world is full of surprises waiting to be discovered, with peculiar, fascinating formations highlighting the delicate balance of Earth’s ecosystems. Each layer of island on lake on island supports a unique array of flora and fauna adapting to the specific conditions within their microcosmic environments, and it’s essential to cherish and such natural wonders. They represent the beauty and resilience of our planet and remind us it is our responsibility to be stewards of the environment. By preserving these unique formations’ environmental qualities we can ensure that future generations will also have the opportunity to witness and appreciate them.
The start of this month saw the marking of World Tsunami Awareness Day. Following up on this subject, let’s explore what a tsunami actually is and discover the stories of some of the most devastating in history.
The word ‘tsunami’ is Japanese, meaning ‘harbour wave’. Tsunamis are essentially large waves caused by oceanic earthquakes or volcanoes. When an earthquake occurs, or there is a volcanic eruption deep under the ocean, the water around it is displaced and often forms a large wave. As the wave moves closer and closer to land it grows taller as the ocean shallows close to shore (as shown in the visual above.) Not all earthquakes and volcanoes will cause a tsunami but one way to predict them is if the water at the shore begins to quickly recede after an earthquake. Tsunamis can be hundreds of feet tall and travel extremely quickly, so they can be incredibly destructive for the areas affected by them. Below are a couple of examples of some of the worst to have been recorded.
One of the deadliest tsunamis ever occurred off the coast of Sumatra on the 26th December 2004. A magnitude 9.1 earthquake created a wave that towered 50m tall and reached 5km inland. It is estimated to have cost around US$10 billion of damage and killed around 230,000 people.
Another of the more recent tsunamis to have caused a great deal of devastation struck the coast of Japan on the 11th of March 2011, having begun with a 9.0 magnitude earthquake. With waves 10m high and arriving at an especially rapid speed of 800km per hour, this tsunami killed more than 18,000 people and displaced around 452,000 whose homes had been destroyed. As well as generating the tsunami, this earthquake caused a nuclear emergency at the nearby Fukushima Daiichi power plant, which began to leak dangerous radioactive steam. The damage that this natural disaster caused is estimated to have been in the region of $235 billion.
As mentioned, tsunamis are not only caused by earthquakes. The Krakatau, or Krakatoa, volcano is located on a small Indonesian island in the Sundra Strait between the larger ones of Java and Sumatra. When it erupted on the 27th of August 1883, it caused waves as high as 37m to form. This tsunami destroyed the towns of Merak and Anjer on Java, and its effects were felt as far away as India and Sri Lanka too. The event killed around 40,000 people in total, though many of those deaths were directly caused by the volcano, rather than the tsunami.
Tsunamis don’t just occur in East and South-East Asia. On the 1st of November 1755, three waves struck the west coast of Portugal and southern Spain. These tsunamis, which reached up to 30m high, together with the earthquake that caused them, killed around 60,000 people in Portugal, Spain and Morocco.
For more information about tsunamis, and of the most powerful in history, visit What Is a Tsunami? at NASA’s Space Place website – and The 10 Most Destructive Tsunamis In History at australiangeographic.com.
The field of archaeology holds a fascination for uncovering the mysteries of ancient civilisations and lost worlds. Traditionally, archaeologists rely on painstaking excavation, analysis of artefacts, and interpretation of historical records to piece together the past. However, a new tool has emerged that is revolutionising the field: generative artificial intelligence (AI). By harnessing the power of AI-powered simulations, archaeologists can now reconstruct and visualise these lost worlds in ways previously unimaginable.
Generative AI refers to the use of machine learning algorithms to create new content based on patterns and data it has been trained on. In the context of archaeology, generative AI can analyse existing archaeological data, such as artefacts, ruins, and landscapes, and generate realistic simulations of what these ancient sites might have looked like in their prime.
One application of generative AI in archaeology is the reconstruction of ancient cities and buildings. By feeding the AI with data from excavated remains, historical texts, and artistic depictions, it can generate 3-D models and visualisations of the structures as they would have appeared centuries or even millennia ago. This technology allows archaeologists and historians to digitally step back in time, exploring the architecture, urban planning, and daily life of ancient civilisations.
Generative AI simulations also aid in understanding ancient landscapes and environments. By analysing geological data, climate records, and flora and fauna distribution, AI algorithms can recreate past ecosystems and landscapes. This enables researchers to study how ancient peoples interacted with and adapted to their surroundings, shedding light on topics like agricultural practices, resource management, and the impact of climate change on past civilisations.
Moreover, generative AI can help fill in the gaps left by incomplete or damaged artefacts. For instance, if an archaeologist discovers a fragment of a pottery vessel, AI algorithms can analyse similar pottery styles and designs from the same time period to generate a digital reconstruction of the complete vessel. This not only provides a more comprehensive understanding of the artefact but also offers insights into artistic techniques, trade networks, and cultural exchange.
AI-powered simulations also have the potential to enhance public engagement with archaeology. By creating immersive virtual reality experiences or interactive applications, people can virtually explore reconstructed ancient sites, walk through ancient streets, and interact with virtual inhabitants. This technology brings ancient civilisations to life, making history more accessible and engaging to a wider audience.
However, it is important to note that generative AI in archaeology is not a replacement for traditional archaeological methods. It is a complementary tool that enhances our understanding and visualisation of the past. Human expertise, fieldwork, and careful analysis of archaeological evidence remain crucial in interpreting and contextualisation the insights generated by AI simulations.
Generative AI in archaeology opens up new possibilities for exploring and understanding lost worlds. By harnessing the power of AI algorithms, archaeologists can reconstruct ancient cities, landscapes, and artefacts with a level of detail and accuracy previously unattainable. This technology not only aids in research and interpretation but also enhances public engagement and appreciation of our shared human history. As the field of generative AI continues to advance, we can expect even more remarkable discoveries and insights into the depths of the past.
Serendipity, that delightful phenomenon of stumbling upon something valuable or unexpected by chance, often transcends the boundaries of time and place. In the world of geography, it can unveil a fascinating tapestry of connection between seemingly unrelated locations and discoveries.
One example of the geography of serendipity lies in the story of the spice trade and the exploration of new trade routes during the Age of Discovery. As navigators and explorers set sail in search of exotic spices, they inadvertently encountered new lands and cultures. The pursuit of valuable commodities like cinnamon and pepper led to the discovery of distant lands such as the Americas and the circumnavigation of the globe. The paths of commerce and the hunger for spices brought together people and places in unexpected ways, forever altering the course of history and shaping the world we know today.
Another example can be of course found in the field of archaeology. Often, extraordinary discoveries occur when explorations diverge from their original objectives. China’s famous terracotta warriors, for example (pictured), were only discovered in 1974, when a farmer stumbled on some pottery fragments while in the process of digging a well.
Archaeologists seeking to uncover the remnants of one ancient civilisation may stumble upon the ruins of an entirely different culture, opening a window into a previously unknown chapter of human history. These chance encounters shed light on forgotten civilisations, challenge existing narratives, and offering fresh perspectives on the interconnection of our past.
The geography of serendipity also manifests itself in scientific research. Scientists exploring one field of study may unexpectedly stumble upon connections or phenomena in seemingly unrelated disciplines, leading to groundbreaking discoveries. For instance, the accidental discovery of penicillin by Alexander Fleming, stemming from a contaminated Petri dish, revolutionised the field of medicine.
Serendipity also reveals itself in the natural world, where unique ecological connections and surprising adaptations can be found. Remote and isolated ecosystems, seemingly detached from the rest of the world, often harbour extraordinary species and intricate ecological relationships. Serendipitous encounters with rare and elusive creatures or the discovery of resilient plant species in unexpected habitats remind us of the resilience and adaptability of life.
In unravelling the geography of serendipity, we come to appreciate the profound influence of chance encounters and unexpected connections. It reminds us that the world remains full of hidden surprises, waiting to be uncovered by the curious and open-minded. Serendipity teaches us to embrace the unexpected, to venture beyond the confines of familiar paths, and to embrace the potential for discovery in every corner of our planet.
If you want to read about a recent example of a fortunate, potentially history changing find, follow this link to the BBC website, with a report on a dig in Zambia which has unearthed the possibility that we may have been building our homes a lot earlier than we thought.
Perfectionism is not, in and of itself, a negative trait. Perfectionists are often conscientious high achievers; our greatest weakness is also our greatest strength. But those trying to be constantly perfect can find that every task feels like an unconquerable burden and every essay a path to failure, however unlikely our friends and family might find our doom-laden predictions. Here are three thoughts to use to beat the unrealistic idealism that may currently be beating you.
What is perfect, anyway? Maybe you could decide. Perhaps perfection could simply mean sitting down at your messy desk, ignoring the clothes on the floor, and spending 10 minutes planning the first half of your essay. In this deeply imperfect and challenging world, if you were to be reasonable with yourself, your definition of perfect should, and could, be different. Redefine perfection: make it doable and make it your own.
A to-do list is a depressing sight, if, at every item, we are telling ourselves that we ‘have to’ or ‘must’ do this or that. But turn ‘have to’ into ‘get to’ and suddenly life seems more joyful. Perhaps it is an irritating piece of advice, an unwelcome call to simply have more gratitude, but studying is essentially an overwhelmingly positive thing. You are learning and growing, and you have access to great materials and educated teachers; you are lucky. And so, even if it feels at first like you are lying to yourself, tell yourself, next time you inspect your to-do list: “I get to plan my essay today”.
We will do it, but we are waiting for the perfect time when we are in the mood. Because we know we can do it well, and not just well but REALLY well. And so that is the aim. This isn’t laziness, for the fear is real: we cannot bear to submit anything less than our best; we cannot tolerate failure; and we want to be proud of what we have achieved. We have visualised (or we think we have) the perfect essay or assignment. But the truth is that you have a deadline. Perhaps you could achieve perfection if you had eternity to complete it. But you don’t. Most tasks have a timeline, whether it is 6 years to complete a part-time PhD, or one night to finish an essay. And the test is not what you can achieve, but what you can achieve in the time you have to complete it. The definition of perfect might simply be this: finished.
Volcanoes erupt when magma (molten rock) from deep under the earth works its way up through the earth’s mantle and crust, forcing its way through weaker rock, before breaching the surface of the earth. Some eruptions are explosive whilst others ooze lava slowly. An active volcano is defined as one that has erupted within the last 10,000 years and is expected to erupt again. By that definition, there are 1500 active volcanoes in the world today, with three-quarters of them located along the Pacific ‘Ring of Fire’. But active volcanoes don’t necessarily erupt all the time and there are around 50 to 70 volcanic eruptions each year. Let’s take a look at some of the world’s most active volcanoes.
Mount Etna is the largest active volcano in Europe. It first erupted around 500,000 years ago and has been continuously erupting for the past 3500 years. In Greek mythology, Zeus, the ruler or the gods, trapped the one hundred-headed monster, Typhon, beneath the ground. Typhon’s rage at his imprisonment causes rivers of fire to pour out of the mountain. Italy is home to two other active volcanoes – Stromboli, known for its violent bursts of lava, and Mount Vesuvius, the volcano that brought about the destruction of Pompeii in 79 CE.
Found on Hawaii’s Big Island, Kilauea is situated on the south-east slope of the neighbouring volcano, Mauna Loa. Initially it was thought that Kilauea was a satellite of Mauna Loa, but recent research has shown that it has its own system of magma tunnels. The volcano has caused the destruction of much of the surrounding area and so local people often leave flower leis as offerings to the fire goddess Pele who, it is believed, lives in the lava lakes of Kilauea’s Halema’uma’u crater. Mauna Loa, the largest volcano on Earth, is thought to have been erupting continuously for the past 700,000 years.
This volcano caused havoc for the commercial aviation industry in the spring of 2010 when a series of eruptions sent huge clouds of ash into the sky, covering a large area of northern Europe. The eruptions continued from March until June that year forcing 20 countries to close their airspace for a week in April as it was too dangerous to fly, disrupting the travel plans of millions of passengers.
This volcano, thought to have produced more lava flow than any other volcano in the world, also wreaked havoc in 2010 when it began to erupt in October. The series of eruptions continued for weeks, causing the deaths of over 350 people, and leaving thousands more homeless after destroying hundreds of homes. In a 1994 eruption, the volcano claimed the lives of 64 people. It is the most restless of Indonesia’s 130 active volcanoes, with smoke continuously rolling across the mountaintop.
Situated on Ross Island, Mount Erebus is the southernmost of all the world’s active volcanoes and is home to one of the planet’s small number of permanent lava lakes. This volcano is also known for its fumaroles; vents in the Earth’s crust which allow steam and gas to escape, creating huge snow chimneys as the steam instantly freezes.
If you’re interested in learning about the most recent volcanic eruptions, you can view data about them the at the Global Volcanism Program website.
Since the dawn of civilisation, humans have sought ways to navigate and understand their surroundings. Mapping, the art and science of creating visual representations of the Earth’s surface, has played a crucial role in this endeavour. From ancient cartography to modern GPS systems, mapping technology has undergone a remarkable evolution, revolutionising how we explore and navigate the world. In this article, we will trace the journey of mapping technology, highlighting key milestones and the impact they have had on our lives.
Mapping has its roots in ancient civilisations, with early examples dating back thousands of years. Ancient cultures, such as the Sumerians, Egyptians, Greeks, and Chinese, developed rudimentary maps to assist in land surveying, trade routes, and military planning. These early maps were often hand-drawn on materials like papyrus, clay tablets, or animal skins, depicting geographical features and landmarks.
The Age of Exploration in the 15th and 16th centuries spurred advancements in cartography (the drawing of maps). Explorers like Christopher Columbus and Ferdinand Magellan relied on maps to navigate uncharted territories and chart new routes. Pioneers in cartography, such as Gerardus Mercator, developed projection techniques that allowed for more accurate representations of the Earth’s curved surface on flat maps. These advancements laid the foundation for those we still use today.
The 19th and early 20th centuries brought about significant advancements in mapping technology. Aerial photography became a game-changer, enabling the creation of detailed maps from above. In 1858, French photographer Gaspard-Félix Tournachon, known as Nadar, captured the first aerial photograph from a hot air balloon. This technique revolutionised cartography, providing a bird’s-eye view of landscapes and enabling greater precision and detail. Topography (def. The arrangement of the physical features of an area of land) also emerged during this period. These new maps combined geographical and geological data to represent three-dimensional terrain on a two-dimensional surface. Topographic maps became crucial tools for military planning, infrastructure development, and environmental analysis, providing valuable information about landforms, elevation, and natural features.
The advent of computers and digital technology brought about a seismic shift in mapping. Geographic Information Systems (GIS) became widely used, allowing for the integration and analysis of geospatial data. GIS enabled the creation of dynamic, interactive maps that could overlay various layers of information, such as population density, land use, and environmental data. These maps became indispensable tools for urban planning, natural resource management, and disaster response.
The most transformative development in mapping technology came with the introduction of the Global Positioning System (GPS). GPS utilises a network of satellites to determine precise positioning on Earth. Originally developed for military purposes, GPS became accessible to civilians in the 1990s. It revolutionised navigation, enabling accurate real-time positioning and providing turn-by-turn directions to individuals worldwide through portable GPS devices and smartphone applications.
Mapping technology continues to evolve in the digital age. High-resolution satellite imagery, LiDAR (Light Detection and Ranging) technology, and advanced data analytics are enhancing the accuracy and detail of maps. Interactive online mapping platforms like Google Maps and OpenStreetMap have become ubiquitous, providing easy access to maps and driving directions on a global scale. Augmented reality (AR) and virtual reality (VR) technologies also hold the promise of immersive and interactive mapping experiences, transforming how we explore and understand our environment.
Rivers are vital to our planet in many ways and yet globally, many are facing increasing pollution challenges. Industrial and agricultural activity, climate change and an increase in microplastics are some of the major contributors to the difficulties. While there are ongoing positive steps to improving river water quality in some areas, increased efforts are needed to address these greater challenges and threats.
Rivers provide a primary source of freshwater for many ecosystems. They support a wide range of plant and animal species, facilitate nutrient cycling, facilitate migration routes and provide a valuable environment for breeding.
Waterways such as the UK’s chalk streams are fragile environments and are some of the rarest, most precious types of freshwater in the world. One species in particular, the mayfly, depends on clean habitats such as these to survive. They are highly susceptible to low levels of pollution and it is estimated that 80% of their eggs are destroyed by contaminated rivers each year. This has led to a drastic decline in their population.
Many communities depend on rivers as a fresh source of water for drinking, cooking and cleaning. When rainfall is low, rivers can be used as a means of irrigation, increasing agricultural output and providing food security. Farmers can irrigate their fields during dry seasons and even expand the area of cultivable land to previously unproductive areas.
Our rivers can be polluted in a number of ways. Despite improved industrial practices and regulations, accidental spillages and illegal dumping can lead to pollutants such as heavy metals, chemicals and wastewater entering natural waterways. Agricultural runoff can introduce pesticides, fertiliser and animal waste; urban stormwater runoff can increase the levels of chemicals and litter, and inadequate sewage treatment and infrastructure can lead to the discharge of untreated sewage into rivers.
Climate change also plays a part in river pollution by exacerbating these issues; higher levels of rainfall can increase the amount of runoff while changes in temperature and water levels can affect the delicate balance of river ecosystems.
An imbalance of nutrients and chemicals in rivers can lead to eutrophication – a growth of algal blooms and depletion in oxygen levels. Increased levels of harmful bacteria and pathogens can pose a threat to water quality and human health while the high level of plastics and microplastics (plastic particles less than 5mm) found in natural water sources are becoming an increasing concern. Microplastics can be digested by aquatic organisms and enter food chains, causing potential harm to humans and animals. Microplastics have already been discovered within our bodies’ organs and tissues and it is estimated that we consume a credit card’s worth of plastic each week!
By implementing a combination of government action, public involvement and responsible practices, we can ensure the long-term sustainability of our essential water resources. The River Mersey, once one of the most polluted rivers in Europe, has made a remarkable recovery over the years. It’s success story that demonstrates it is not too late to reverse the damage that pollution has caused to our rivers and that we can still make a positive impact on their recovery.
Find out more about fragile environments and their value to our planet through Oxford Open Learning’s flexible Geography IGCSE accredited distance learning course. Get in touch with us today to find out more.
Whatever subject you are studying or qualification you are studying for, contact with your teacher or tutor – even when remote – is an invaluable part of that process. They are usually the subject experts, have a full understanding of the assessment process and have, more often than not, supported many other students who felt exactly the same as you do now about their learning. Whether you are confident in your subject knowledge and looking for ways to stretch yourself in order to achieve the very best results or are still a little uncertain and unsure how you might secure the grade you need, your tutors can provide you with the support you require. Here are a few simple strategies every student should try in order to boost the benefits of the contact they have.
Put simply, meet their expectations! If they provide a task, complete it. If they set a deadline, meet it. If you have a meeting, be there. Programmes of study and assessment schedules are in place to meet the needs of everyone; ensuring that there is adequate time for covering all of the content, assessing progress and providing feedback. A tutor works with many students and if you don’t adhere to the plan then you are unlikely to get the time you deserve. If there is a problem with the schedule set out for you, talk to your tutor in advance so that they can make any amendment they possibly can in order to make sure that everyone’s needs are met. If a tutor sees you are committed to your learning and doing what is required they are likely to go above and beyond in the ways in which they support you.
As already mentioned, the tutor is the subject expert. They have the knowledge of the subject but also the ways it is assessed and how to ensure you can demonstrate it when required to do so. Listen to their advice. Take notes where required. Follow their suggestions. However, if there is something you are unsure about, don’t be afraid to ask! Questioning is key to developing a deeper understanding and mastery of a subject but is also a great tool in ensuring there have been no miscommunications or misunderstandings. Your tutor will respect your ability to really engage with the content you are covering together and look for ways to address your questions in more detail.
Receiving feedback is one of the most important parts of the learning journey. However, many of us find getting feedback something that is really, really hard! Instead of thinking about what is said by your tutor as being ‘good’ or ‘bad’, try to consider what you can learn from it instead. If you are given praise for a certain aspect of your work, think about what you did that made this so effective. If there are comments relating to something that hasn’t worked out so well then think about what you might do differently next time. Reflection is key to making progress. Also, apply the same thought process when it comes to your attitude to learning. If a tutor comments on this, avoid taking it personally and think of how you might use what they have said to become a more effective learner.
Don’t forget that any contact that you have with your tutor is designed to benefit YOU. If you are in need of something specific from that contact then, again, do not be afraid to ask! In reality, this involves planning and preparing for any contact you have before you have it. Make a note of any questions you have when studying independently. If you need to revisit any material with them, ask in advance. If you have found a subject area particularly easy or hard, let them know. Remember, your tutor will be looking to support you in a way that is personalised to meet your needs too, so the more effectively you’re able to communicate these, the better they will be able to do this.