Causes of earthquakes in south africa pdf

South africas second national climate change report. It is difficult to correlate the seismic foci with geological features in a clear and definite manner. The seismicity of africa, especially southern africa is, by world standards, very moderate and of shallow character. The seismicity or seismic activity of an area refers to the frequency, type and. The surface where they slip is called the fault or fault plane. Earlier on, the inhabitants of east africa were food gatherers, but. Only a few tenuous correlations can be made with the surface geology. What is an earthquake and what causes them to happen. The location below the earths surface where the earthquake starts is called the hypocenter, and the. The main causes of earthquakes fall into five categories.

The tectonic plates are always slowly moving, but they get stuck at their edges due to friction. People living along plate margins are at risk of being affected by earthquakes. Umvoto africa pty ltd, po box 61 muizenberg 7950, south africa. Most of what we know about the interior of the earth comes from the study of seismic waves from earthquakes. Therefore, as a government minister, if you wanted to prevent earthquakes, you would need to. These movements create waves that propagate through the earth. South africas response to climate change was presented. As the other answers have said, mining to an extent. Get information about major earthquakes and secondary hazards fires, landslides, liquefaction, tsunami in coastal areas that have affected the project area in the past and the effects these caused. Earthquakes are one of the most dangerous natural disasters on earth. This has long been apparent from early catalogs of felt earthquakes and is even more readily discernible in modern seismicity maps, which show instrumentally determined epicentres. How to stop the earthquakes in south africa if i was.

Critical evaluation of seismic activities in africa and curtailment. The effects produced by earthquakes including ground shaking, landslides and rockfalls cause damage to property and loss of life. Global warming due to climate change leads to heat waves because of the accumulation of atmospheric gases in the ozone. The principle trigger of earthquakes in south africa is thought by various scientists to be deep underground mining which can activate natural faults.

The earthquakes, south west of africa, were confirmed by the us governments usgs united states geological survey. Impact of recent moderately sized earthquakes in south africa. In ancient times earthquakes were thought to be caused by restless. The climate change annual report reflects on the progress in undertaking these actions with the aim of recognising ongoing actions, quantifying their impact, catalysing new actions and indicating how these actions contribute to the national imperatives of reducing poverty and inequality, and. According to wikipedia, an earthquake also known as a quake, tremor or temblor is the perceptible shaking of the surface of the earth, resulting from the sudden release of energy in the earths crust that creates seismic waves. Earthquakes in south africa september 5th, 2014, published in articles. Earthquakes occur most often along geologic faults, narrow zones where rock masses move in relation to one another. Earthquakes are typically caused by the movement of the earth crusts. Latest earthquakes in the africa region 1 earthquakes of magnitude 4. Earthquakes are the most terrifying and destructive among natural phenomena e. An earthquake occurs because of the movements of tectonic plates beneath the surface of the earth. Earthquakes can be humanmade or natural, although the latter is more abundant. These forces bring about changes on the earth surface and physical features like mountains, plateaus and rift valleys are formed.

Earthquakes are caused by disturbances in the interior of the earth and other causes. Seismic hazard in south africa council for geoscience. They occur without warning and can do some serious ground shaking. Scientists can explain how most earthquakes are caused using simplified theories of the earths structure. Pdf on jan 1, 2002, jane turpie and others published economic impacts of climate change in south africa. Find articles, news, videos, pictures, links and facts about south africa. Earthquakes are vibrations caused by rocks breaking and shifting under stress.

On the contrary, the south of africa has only recorded moderate seismicity over. Until very recently, the cause of earthquakes was an unsolved mystery. Community memory and historical accounts of earthquakes can provide useful information to supplement scientific studies. Thousands of minor tremors often take place just because of these constant movements. Positionit in light of the 5 august 2014 m5,6 earthquake, the council for geoscience held a panel discussion at the csir on the likeliness of similar earthquakes reoccurring in south africa. Earthquakes have occurred on the ancient cratons as well as in the mobile belts. Climate change is a slow, natural cycle that causes the earths temperature to rise and fall periodically over centuries. Like the hundreds of earthquakes that happen yearly in alaska. The quake is the largest in the southern africa region since a 7. Pdf economic impacts of climate change in south africa. Earthquake in oceans is known as tsunami, which is equally devastating. Earthquakes in south africa since 1950 the strongest earthquake in south africa happened on 09291969 in the region cape province with a magnitude of 6. It it not felt in a large population center, or causes visible damage, usually no one knows about it. The southeastern african region covers a region which is prone to a significant level of.

The new academic research into seismic risk in south africa enables aon benfield to improve its catastrophe models by updating provision for both mining related and tectonic origin seismic events. A preliminary analysis of unmitigated damage costs find, read and cite all the research. Earthquake magnitude earthquake severity richter magnitude earthquake effects less than 3. Causes of earthquakes article about causes of earthquakes. The book presents guidelines to visiting 42 different volcanoes around the world. Earthquakes can be violent enough to toss people around and destroy whole cities. Seismic waves from large earthquakes pass throughout the earth. What are the main causes in south africa about earthquakes.

Map of earthquakes 16202008 contained in the south african national seismological. He believes that 95% of south africa s earthquakes are caused by mining, especially around the areas of. Macroseismic investigations of the 18 november and 2 december 20. South africa earthquake latest breaking news and updates, information, look at maps, watch videos and view photos and more. South africa is undertaking significant actions to respond to climate change risks and impacts. Almost every year, earthquakes are recorded in various parts of the world. According to professor andrzej kijko from the university of pretorias natural hazard centre, mining can activate natural faults. These lines are called faults, and are where most earthquakes occur. The councils denver birch says its difficult to prove mining is to blame. This means that there is a 10% chance of potentiallydamaging earthquake shaking in your project area in the next 50 years. East africa were at first using stone tools but when ironsmelting was started, there was an increase in food production. All information you need to know about south africa. The local south african national seismographic network sansn operated by the council for geoscience is capable of accurately locating micro earthquakes of magnitude much less than 3, but unfortunately it no longer makes its seismographic data freely available online, according to hartnady. Earthquakes occur when the ground is subjected to so much force that it fractures or breaks.

However, climate change poses a real risk to these natural assets, as well as to the people who live in this beautiful country. Apr 03, 2012 the impact of climate change on south africa jenny griffin, south africa original post. Dec 19, 2017 seismic hazards in south africa are not high by international norms. Location of recorded earthquakes in southern africa. Most earthquakes are causally related to compressional or tensional stresses built up at the margins of the huge moving lithospheric plates that make up the earths surface see lithosphere lithosphere, brittle uppermost shell of the earth, broken into a number of tectonic plates. An earthquake is caused by a sudden slip on a fault. According to professor andrzej kijko from the university of pretoria s natural hazard centre, mining can activate natural faults.

Earthquakes earthquakes occur when energy stored in elastically strained rocks is suddenly released. South africa s large magnitude earthquakes have a low frequency. For many african countries, earthquake hazard constitutes a serious threat. Pdf large recorded earthquakes in subsaharan africa. Can cause major damage to poorly constructed buildings over small regions. Earths major earthquakes occur mainly in belts coinciding with the margins of tectonic plates. Since the 2006 saeo, local and global research has advanced. The following is a list of notable earthquakes or tremors that have been detected within south africa. South africa has relatively little indigenous forest, with the total cover being less than 500 000 ha, or 0. The science behind earthquakes what is an earthquake. The epicenter was near the village of killari located in the latur district, about 300 miles south east of mumbai. Pdf depths of earthquakes in south africa researchgate. Earthquake, any sudden shaking of the ground caused by the passage of seismic waves through earths rocks.

On a global scale, south africa is considered a stable region, because it is located away from boundaries between tectonic plates. The inset is a map showing the location of the study area in south africa. This is because they strike with little or no warning, and can cause catastrophic damage. Chapter 11 climate change department of environmental. The shifting of tectonic plates in a depth of 32 km resulted in 12 deaths. Worst natural disasters in south africa briefly sa.

The location of the 18 november 20 and 2 december 20 earthquakes is also shown in the figure by the yellow stars and labels. He believes that 95% of south africas earthquakes are caused by mining. Causes, effects and geographical distribution of earthquakes. Learn more about the causes and effects of earthquakes in this article. This release of energy causes intense ground shaking in the area near the source of the earthquake and sends waves of elastic energy, called seismic waves, throughout the earth. Pdf historically, hypocentral depths of earthquakes in south africa are not well documented from instrumentally. He believes that 95% of south africas earthquakes are caused by mining, especially around the areas of klerksdorp, welkom and carletonville. Chapter 4 earthquakes strategic environmental assessment for. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earths crust and cause the shaking that we feel in california there are two plates the pacific plate and the. Map of earthquakes 1620 2008 contained in the south african national.

Earthquakes in south africa today earthquakes today. Another is africa s sparse population, if a tree falls in the woods and no one hears it, does it make a sound. Some of the causes of natural disasters in south africa include. Seismic hazard maps for southern africa by fernandez and du plessis. But a greater cause of the very few earth quakes we have is underground erosion. Pdf impact of recent moderately sized earthquakes in south. In the area you have selected south africa earthquake hazard is classified as medium according to the information that is currently available.

A series of earthquakes of magnitude of about of 6. Seismicity map showing earthquakes magnitude greater than 4. Earthquakes in johannesburg, gauteng, south africa most recent. Posted on november 24, 2017 february 18, 2020 author editor 26. The following is a list of notable earthquakes or tremors that have been detected within south africa according to professor andrzej kijko from the university of pretorias natural hazard centre, mining can activate natural faults. An earthquake is what happens when two blocks of the earth suddenly slip past one another. Two earthquakes strike south west of south africa sapeople. Projections of future temperature and rainfall, and potential impacts of climate change on health, water resources, rangelands, maize, forestry and biodiversity were discussed. Human operations such as mining that can trigger earth tremors due to the displacement of fault lines. Earthquakes are known for being deadly natural disasters. South african run machine conway cleared to play for new zealand. Although climate change is a natural occurrence, human industrial and development activities over the past two centuries have caused changes in climate independent from natural changes.

The cape fold belt and the adjacent karoo basin are equally subject to sporadic activity. Excellent information and background for anyone wishing to visit active volcanoes safely and enjoyably. The most important earthquake belt is the circumpacific belt, which. When the stress on the edge overcomes the friction, there is an earthquake that releases energy in waves that travel through the earths crust and cause the shaking that we feel. Since the shear and tear forces are always constant within the earths plate tectonics, earthquakes can occur at any time. The disturbances inside the earth are called tectonic movements. But there could be significant damage to infrastructure if seismicity increases.