Geology for Global Development

Heather Britton

Is geological mapping becoming obsolete?

Is Geological Mapping Becoming Obsolete?

Geology students typically experience some form of mapping education as part of their course and attitudes towards this baptism into the geosciences vary from adoration to utter hatred. Whatever the opinions of the students, however, it is widely recognised that performing mapping exercises is an excellent way to learn the basics of structural geology which underpins aspects of both further geological education and the use of geology in industry. Unfortunately, the number of graduates using the mapping skills practiced in their undergraduate years is dwindling. There is an increase in the use of seismic and borehole data alone to generate cross-sections through the earth, where field-collected strike and dip data, used alone or in tandem with other methods, can often provide a far better insight into what really occurs under the ground. As the number of graduates practicing field mapping in their careers continues to decrease, we may be reaching a time when mapping skills are lost to all but a few specialists, and even these may eventually disappear.

 

Is geological mapping obsolete?

Drone technology is now used in numerous mapping expeditions. Credit: Chris Sherwood, Woods Hole Coastal and Marine Science Center (distributed via USGS).

Technology and mapping have coevolved over the years, from mapping via horse and cart to the use of drones to pick up larger-scale landscape features that may not be visible at ground level. The question is, as technology develops to simplify many of the physical aspects of mapping will it remove the need for traditional geological mapping altogether? In many ways mapping involves risks that are not encountered in many other professions – trekking off the marked paths abroad can mean coming face-to-face with venomous snakes, bears or wild boar (all of which occurred during my year’s undergraduate mapping projects) and often a quick look at a satellite image of the area can answer questions that days squinting at an outcrop cannot.

Despite these drawbacks, it must be appreciated that there is certain information that can only be obtained by looking at a rock first hand, such as the identities of different minerals and the deformation history of a high grade metamorphic rock. It is for this reason that exploration geologists are becoming increasingly alarmed at the apparent lack of next-generation geoscientists well practiced in the art of mapping.

The potential reasons for this negative trend are numerous – the lower numbers of professional structural geologists teaching next-generation geoscientists, a lack of companies offering mapping placements over the university holidays and fewer students taking up the subject, with the number of schools and colleges offering geology as an A level having dropped substantially over the past few years. At the same time, there has been a noticeable shift towards less fieldwork-focussed university curricula due to the high cost of fieldwork and the liability this presents to institutions,  and a trend toward exploration in regions with more cover, where outcrops can be scarce.Nonetheless, it is very difficult to overestimate the value of mapping – after all, no geological discipline is complete without a map and preventing the decline should become a priority.

Increasing the number of geologists capable of mapping depends on replenishing skills regularly to ensure that techniques developed whilst at university can be maintained until the opportunity becomes available in an industrial setting. Further funding from companies toward the initial university mapping training may also be beneficial, as would the continued emphasis of structural geology in courses that are broadening due to advances in other rapidly growing geoscience fields, e.g. geochemistry. It is also important to appreciate that although mapping may seem old-fashioned it is by no means outdated – maps themselves are today constructed using cutting edge GIS technology, which plays a far greater part in the final product than might be initially assumed from glancing at a student’s notebook.

Is geological mappping obsolete ?

Highly deformed marble and pelite layers. Structures such as this are only visible at hand-specimen scale and it is therefore important that geologists enter the field in order to make these observations. Credit: David Tanner (distributed via imaggeo.egu.eu)

Although geological mapping skills are decreasing, they are far from being lost altogether. As industries appreciate the value of experienced field mapping talent we can hope that the funding will follow, to ensure that this age-old art continues to be practiced for the benefit of not just geological disciplines, but other areas of society too. Geological cartographers may help find mineral veins for mining, or potential aquifers enabling them to provide water to parched communities, helping to achieve SDG 6 (clean water and sanitation). A technique with so much potential should not be allowed to be lost from the world.

 

Heather Britton: China’s Water Diversion Project

Heather Britton: China’s Water Diversion Project

China has enjoyed economic growth over the past decades, bringing undoubted prosperity to the country. But exponential industrialisation and rapid growth comes at a significant environmental cost. The nation is heavily dependent on coal-fired power, making it one of the world’s largest emitters of greenhouse gases and it’s thirst for development is a drain on vital resources, including water. In today’s post, Heather explores how China’s geography accentuates an anthropogenic problem. 

When travelling from the North to the South of China there are number of trends that can be observed – dialects change, the dominance of noodles is replaced with a preference for rice and, crucially, the climate becomes more humid. The South typically receives excessive rainfall, often leading to devastating flooding, whilst the North dries due to the thirst of industry and a booming population. China’s water diversion project aims to solve both problems with one monumental feat of engineering – by diverting 44.8 billion cubic metres of water annually from South to North via a network of canals and tunnels. I’ll explore the impact that this is having on China and its people, and whether it is a sustainable solution to the disparity in water supply across the country.

Water shortage is a constant concern in the North, with the groundwater stores that support the region dwindling to a fraction of what is required to allow the cities and industries centred here to thrive. In addition, more than half of China’s 50,000 rivers have disappeared in the last 20 years. Having experienced unprecedented economic growth over the past few decades, Beijing is on the brink of a water crisis. In the South, flooding is the primary hydrological issue, exacerbated by the drainage of lakes and the damming of rivers for construction. It was commented in the 1950s by Chairman Mao that ‘The south has plenty of water, but the north is dry. If we could borrow some, that would be good’. This statement is heralded as the idea that has grown to become what is now ‘The world’s most ambitious water-transfer program’.

The project is not merely a fantasy – construction on a number of the pathways is already complete or nearing completion, and already over 70% of Beijing’s water is transferred from the South as a result of this project. Costing $62 billion, there is a clear driving force for the project – the thirsty North is running out of water fast, and although an extreme move, it is true that this project will provide some vestige of relief – but for how long, and at what cost?

Millions have benefitted from the water transfer and it certainly is a solution to the disparity in water supply between the North and the South of the country, but it is also arguably one of the worst. China’s demand for water is growing so quickly that even before the project’s completion in 2050 further solutions are likely to be required, and industrialisation along diversion routes poses a serious pollution threat. Salinization  of some waters heading North seems inevitable. An even larger concern is that the South may no longer have enough water to spare – the Han river, an important tributary to the Yangtze, is planned to have 40% of its water diverted to the North, but the towns and cities situated along its course are already experiencing water shortages. Furthermore, 345,000 villagers have been displaced from their homes to make way for the new water courses, often to lands and property far inferior to what they were promised and what they left behind. It is clear that the project is far from sustainable.

It would be wrong, however, to say that the Chinese government is doing nothing to reduce the impact of the scheme. Addressing environmental concerns in the Danjiangkou reservoir, a $3 billion ecological remediation package has been put together, and the water diversion project has allowed the groundwater reservoirs in Beijing to rebound by at least 0.52m. The environmental threat persists, however, and it seems unlikely that retrospective measures will be able to dissipate all of the environmental risk. By considering more sustainable solutions, the impact on the land and the people of China could have been drastically reduced. The Chinese vice minister of Housing and Urban-rural development has called the project unsustainable, acknowledging that, in the case of many cities, recycled water could replace diverted water. If efforts were focussed on water desalination technology and the collection of more rainwater, rather than the creation of multiple colossal aqueducts with unsavoury environmental consequences, then water resource management could be tackled in a far more sustainable manner.

Effective water conservation is something that is becoming a larger and larger problem for the Global South, particularly in the drier parts of the world. The water diversion project acts as an interesting case study, and shows the repercussions of dramatic engineering solutions to water resource problems. Although possible from an engineering perspective, forcing a change in the hydrological system of a country is rarely without its complications (and substantial expense). Lessons can be learned from the water diversion project, and future Global South nations should think twice before entering into any project of such scale without considering the full implications or other, more sustainable options. Doing this would help towards the achievement of UN Sustainable Development Goals 11 (sustainable cities and communities) and 6 (clean water and sanitation).

Peat in the Tropics

As has been previously discussed in Robert’s blog, fertile soil is an incredibly important resource that is fast running out in many regions of the world. It is true that soil’s importance for agriculture (and sustainable development) cannot be understated, but I wish to focus on another aspect of soil in this week’s blog– its ability to store carbon.

One soil type in particular, peat, is an incredibly important form of carbon storage. Despite only covering 3% of the Earth’s land surface it contains a third of the carbon stored in soils, formed by the build-up of partially decomposed organic carbon, trapped in waterlogged and anoxic conditions. For this reason the preservation of peatland is of the upmost importance, and should be considered in sustainable development efforts in order to prevent the release of vast amounts of carbon into the atmosphere.

Figure 1- Distribution of mires around the world. Source: International Peat Society, Available www.peatsociety.fi

When you picture peat it is typically in a cool and damp climate, such as in the highlands of Scotland or expanses of tundra within the Arctic Circle. This is because the cooler climates further impede the decomposition of organic matter and facilitate the formation of peaty soils. Recently, however, it has been discovered that peat forms in other regions too, and in quantities far vaster than had ever been considered before. These tropical peat deposits form in the swamps commonly found in the river basins of warm and humid regions. Although warm and wet conditions typically aid the processes of rot and decay, the often stagnant water of swamps produces anoxic environments not dissimilar to those in the extensive peatlands found at higher latitudes. Conditions are exacerbated by poor drainage, high rainfall and overbank flooding by rivers, meaning that the land never truly gets the opportunity to dry out and peatlands are able to form, albeit in much smaller expanses than those in the North.

Despite the smaller size of tropical peat deposits they are disproportionately more significant to sustainable development, as they tend to be focussed in regions where development is occurring rapidly – central Africa, South East Asia and South America. Building on and draining these fragile ecosystems could result in mass release of carbon dioxide.

An example of a tropical peat deposit is the Cuvette Centrale depression in the Central Congo basin, where the peat is relatively shallow (with a median depth of 2m), but has a large aerial extent, making it the greatest ranging peatland in the tropics. Other extensive peat deposits can be found in the amazon rainforest and in tropical Asia (for example the island of Borneo) but land use changes in recent years have drastically reduced the amount of peatland in SE Asia, as much has been drained for agricultural use. It is predicted that SE Asian peatland will be lost completely by 2030, but thankfully the peatlands in other areas of the world are in a significantly more pristine condition, relatively unaffected by humans due to their relative inaccessibility.

Drainage of land for agricultural use is not the only threat to tropical peatlands. Climate change is acting to reduce the annual precipitation in many tropical regions, meaning carbon trapped in peat is oxidised more readily and able to decompose. Even though tropical peatlands are only a fraction of the size of their northern, cooler cousins, they still represent huge carbon stores that, if destroyed, could accelerate the release of carbon into the atmosphere and accelerate global warming further, entering into a feedback loop which will release tonnes of carbon into the atmosphere that has lain trapped underground for millennia. Carbon stocks of peat in the Cuvette Centrale alone are potentially equal to 20 years of current fossil fuel emissions from the USA, demonstrating the importance of protecting this seemingly insignificant soil type.

Figure 3 – SE Asian rainforest. It is in rainforests such as this that peatlands are quickly being drained for agricultural use. Source: https://imaggeo.egu.eu/view/4268/

A further concern is that swamplands are a refuge for many of the world’s remaining megafaunal populations, including lowland gorillas and forest elephants. It is clear that if Africa and South American peatlands are to avoid the fate of the SE Asian counterparts, they must become a conservation research priority.  Doing this would undoubtedly help to combat the rise of CO2 levels and simultaneously work towards the UN Sustainable Development Goal 13 – climate action.

Heather Britton: Can Animals be Used to Predict Earthquakes?

One of the most common questions faced by the disaster risk reduction community relates to earthquake prediction (see this Geological Society briefing on prediction vs. forecasting). The disaster risk reduction community, however, would perhaps argue that improved buildings, reduction in poverty, and improved governance are a greater priority than predicting earthquakes. Even so, there are still many members of the international community focused on trying to identify ways to predict earthquakes, including through the study of animal behaviours.

Our understanding of where earthquakes are most likely to occur is improving, but our ability to predict when an earthquake will strike is lacking, often limited to the decadal scale at best. We also lack information on what the magnitude or size of an earthquake would be at that given point in time. If such a feat were possible, and an orderly evacuation could take place, lives could be saved. Many seismologists are of the opinion that the vast majority of earthquakes do not display early warning signals prior to the first p-waves reaching the surface, therefore earthquakes are likely to always remain stubbornly unpredictable. This does not mean that we will be unable to improve earthquake forecast, through probabilistic hazard assessment. It also does not mean that the disasters arising from earthquake are inevitable. We can still take significant steps to reduce exposure and vulnerability and reduce the impacts of earthquakes.

Other scientists disagree,  on the point of earthquake prediction, pointing to the anecdotal evidence which stretches back through historical archives around the world of animals predicting earthquakes far before modern technology would have us believe any indication of an earthquake existed. Is there any substance to these tales, and if so can it be used to support earthquake prediction?

Although devoid of substantial scientific evidence, the claim that early warning signs don’t exist fails to acknowledge the stories of animals abandoning their homes up to a month before an earthquake strikes. For centuries there have been reports of unusual animal activity prior to earthquakes: In 373 BC Greece it is documented that rats, weasels, snakes and centipedes abandoned their homes a month before a destructive earthquake struck, and in Italy toads disappeared from a pond where scientists were analysing their breeding patterns just days before a magnitude 5.9 earthquake killed over 300 people in 2009. Perhaps these animal behaviours can be used to predict the occurrence of earthquakes, but without knowing the nature of the signals which trigger their response it has limited applications in disaster risk reduction.

Figure 1- Frogs on logs. It has been suggested that aquatic organisms such as these may be able to predict earthquakes from changes in groundwater chemistry. (Source: https://www.pexels.com)

The problem with focusing so much on anecdotal evidence is that the stories are often augmented by the human imagination, an effect often seen in the game ‘Chinese Whispers’.  The result is that the unusual behaviour apparently displayed by the animals before earthquakes occur can become exaggerated and, in many cases, the reports only appear after the earthquake has struck. It is very well announcing a pet’s unusual behaviour after the disaster, but had the earthquake not occurred would the behaviour still have stood out as being so strikingly abnormal?

Animal behaviour is extremely complex and using this as a metric for earthquake prediction is not considered to be feasible because of the inconsistency of animal responses. This has not prevented at least one Chinese city from installing 24-hour surveillance on a snake farm with the intention of detecting unusual behaviour for the purposes of earthquake prediction. In 1975 officials successfully evacuated a city of one million people just before a 7.3 magnitude earthquake in Haicheng, China, purportedly based on abnormal animal behaviour. However, this has been rejected as substantial evidence for the power of animal foresight as this earthquake was one which was preceded by a number of low magnitude foreshocks which are thought to have given the governing body of Haicheng the confidence to evacuate the city, under the impression that a larger earthquake was on its way.

Figure 2 – Aftermath of an earthquake in 1971, San Fernando, California. Source:  USGS
Denver Library Photographic Collection.

As is almost always the case, the evidence from a number of different studies is contradictory and inconclusive, implying that the predictive signals, if present, may vary between earthquakes. Evidence for the ability of animals to predict earthquakes was found in a study in Peru – no animal movement was recorded by camera traps on the rainforest floor (an extremely unusual observation) five out of the seven days leading up to the magnitude seven Contamana earthquake that affected the area in 2011. Other studies, however, such as those performed in the 1970s by USGS, have found no correlation between earthquakes and the agitation of animals.

The evidence is patchy, but if there truly is a relationship between animal behaviour and earthquakes the identity of the signal that the animals are responding to remains a mystery. A paper released in 2011 describes a mechanism by which stressed rocks could release charged particles. These particles could then react with groundwater, producing chemical signatures which may be detected by aquatic and burrowing life. Other suggestions of potential signals include ground tilting, although this would have to be present only at miniscule levels not to be detected by current technology, or variations in the Earth’s magnetic field.

Currently research into the use of animals in earthquake detection is being led by Japan and China, two countries regularly affected by earthquakes and where a plethora of anecdotes relating to the powers of earthquake prediction by animals have originated. While earthquake prediction could help to reduce the impact of earthquakes on society, there are far more effective and immediate things that we can do. Ensuring properly constructed buildings and enforcing building codes, tackling the underlying social vulnerability (e.g., poverty, inequality) and improving governance structures and earthquake education are some examples.

Read more about disaster risk reduction in the UN Sendai Framework for Disaster Risk Reduction.