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In May, the Arch of Darwin’s Arch in the Galapagos Islands collapsed into the sea due to natural erosion. Recently, a 200 foot piece of Pictured Rocks fractured and slipped into Lake Superior. Getting the Michiganders to wonder if record-breaking 2020 Great Lakes water levels could increase coastal erosion on Michigan’s beloved landforms and lakeside homes?
Danita Brand T, associate professor at Goment of earthh and environmental sciences within the College of Nayou raI Science at Michigan State University, explains how erosion is a natural process that inevitably alterss landscapes on geological time scales.
Phanikumar Manta, pprofessor in the Department of Civil and Environmental Engineering within the College of Engineersmg at MSU, explains what we can do to mitigate the effects of coastal erosion on human timescales.
1. What is coastal erosion?
Brandt: Coastal erosion is the result of the interaction of waves, currents, wind, ice and gravity with a shore. It is a natural part of the Earth’s surface processes which include weathering, erosion, transport and sediment deposition and rocks.
Mantha: Coastal erosion collectively refers to the processes of decomposition, pick up and take away material (for example, rock or sand particles) along our coasts by moving water and / or wind. Wthe water of the hens slows down down, the particles are abandoned, aand the process is called deposition. Erosion and deposition are two sides of the same coin and these are the same Natural processes that shaped our shores in the past and continue to shape them today.
2. How is coastal erosion affected by the Great Lakes?
Brandt: The impact of coastal erosion in Michigan is directly linked at lake levels; higher lake levels average more erosion. Last year’s record lake levels affected all Michigan residents, either directly or indirectly, as not only private homes but also facilities in our waterfront state parks were damaged or destroyed. The level of the lakes fell this spring, just in time to help rejuvenate the economies of local lakeside communities by exposing more beach. We are a state of two peninsulas. We will always have to fight against coastal erosion. The “extent of the problem” of coastal erosion in Michigan will be determined by how we think about this natural process – as a “problem” to be solved (temporarily) by engineered solutions or as a fact of living on a dynamic planet and the complexities that this entails.
Mantha: The water currents in the great lakes are mostly driven by the winds. When Wave and current patterns change locally (due to nature process or human activities), they or they can trigger changes in erosion / deposition models. we live a higher frequency of extremes wind speeds and bigger waves as the surface temperatures of the lake increase and this results in higher erosion potential. In addition, hupper lake levels and shrinking ice cover on lakes lead to more erosion. Winter ice cover can shield surface wind effects water while protecting the shores from strong winter waves. however, decreased ice cover on the Great Lakes means that erosion and impacts on the coast keep happening during the winter months as well as.
3. How does coastal erosion threaten Michigan’s landforms – such as beaches, sand dunes, or large rock formations – and lakeside homes?
Brandt: Erosion is a natural process. It becomes a threat or a problem when humans – our lives, property or livelihoods are affected. “Natural processes” – volcanism, earthquakes, floods, erosion (massive loss) – to become “Natural disastersâWhen humans are affected. Earth is a dynamic system. Natural elements and human structures, such as houses, are ephemeral, geologically speaking; they can last for a long time on a human scale, but the Earth is constantly changing, responding both to the internal forces that build mountains and cause earthquakes and give rise to volcanoes, and to the external processes that are fueled by the terrestrial atmosphere and hydrosphere.
Presenting the discussion of the erosion and eventual collapse of these structures as a ‘threat’ fails to recognize the inevitability of the natural outcome and often leads to costly and ultimately futile efforts to deny the reality of Earth’s constant change and the need to work in this reality.
Mantha: Erosion and deposits are natural processes that will always be there. Our coastlines are constantly evolving in response to changes in flowes of sediment delivered to coastal regions by rivers, lake currents and wave action. Tit means that if we examine the sediment balance – the amount of sediments entering and leaving an area of ââinterest – we find that some areas along the coast are the boneis lying sediment while other areas are to win. the rate of these natural processes accelerate as the intensity and frequency of extreme storms increase with undesirable consequences (for example, houses by the sea are collapsing the lake following the erosion of the cliffs, lost beaches, lost sand dunes, etc.).
4. Is there anything humans can do to stop or at least slow down coastal erosion?
Brandt: Yes. AT To the extent that we humans contribute to climate change, especially global warming, which causes sea level rise and more frequent and violent storms, we strength slow coastal erosion by taking measures to reduce levels of carbon dioxide emissions in the air.
Mantha: Yes. In addition to taking steps to reduce CO levels2 in the atmosphere, we can start by (a) take steps to protect our coastal wetlands that help prevent erosion (b) Planning carefully when it comes to designing and building coastal structures as they often have unintended consequences and may exacerbate local vulnerabilities in a warming climate (vs) be careful of and rethink upstream activities (for example, irrigation systems) this may decrease sediment input in coastal areas (re) eradicating invasive plant species and breminiscent of plants and herbs native to our shores areas to stabilize the soil etc. In areas where erosion is a major problem, bank stabilization works for some of time, But he May be a temporary solution. WAves have a big role to play in sediment transport (wave power is proportional to the square of the significant wave height); therefore, approaches based on reducing the destructive power of waves as they approach the shore have been used in the past (for example, underwater structures designed to dissipate wave energy). These solutions tend to be expensive, But.
5. If we can’t stop coastal erosion, what could Michigan look like in the future?ure?
Brandt: We tend to think of mountains and continents as immutable, permanent monoliths that have always been where we find them today and enduring forever, but Earth’s tectonic plates move at an average speed of 2 cm / year; Earth 250 millions of years ago was very different from today, and the Earth from 250 million years into the future will be very different from today.
Mantha: Process managementis lying stransport of ediments are complex and highly nonlinear – a direct the consequence is that long-term forecasts over large areas involve significant uncertainties. This shouldn’t prevent us from acting now to prepare for future changes., But. Coastal communities in other parts of the world have shown remarkable resilience and have adapted to change, and we can learn from these lessons. It also helps in planning to separate the climatelinked to you changes of no–weather impacts. At the end, a combination of solid science, innovative engineering solutions, policy and investment in coastal research, education and awareness will help us move forward.