Blog 4 - Die Entscheidung (The Judgement)

Tectonic map of plates surrounding the Mediterranean basin at present

We have seen over the semester the power of nature to constantly transform itself and the part humans have played in this especially in the last 10 millennia. Now we will look toward the future and try to predict the future transformations in our particular region of the study, the Rhine-Main basin. Tectonics, volcanism, glacial movements, erosion, and most recently, anthropomorphic "improvements" have all worked together to shape the Rhine-Main basin we see today. Our planet is a living and dynamic one geologically and will be so for a long time yet in human terms, By looking back at the previous trends we have covered, we will be able guess at the future shape of the land, of course excluding any dramatic extraterrestrial events such as asteroid impacts. 

Europe after the last glacial period

10,000 years from now... 

Tectonicly, not much will have changed yet as the movement of the plate is a slow process from a human point of view. We also supposedly aren't due to enter another glacial period for at least another 25,000 years. Yet it is important to remember that these are not the only methods by which our geography can change. 10,000 years ago as Europe emerged from the grips of the last glacial period, the banks of the Rhine were covered with forests of coniferous trees which have since shifted northward to Scandinavia as the climate changed along with various animals that either went extinct or also moved North.

The shape of the rivers themselves will be very dependent upon if we are still living around and using it. 10,000 years ago, the humans that lived in the area had no control over them, but, as we covered in Blog 2, we have gained control by daming, canals, dredging, and straighten the rivers to suit our needs. If humans are still living a "civilized" life in the area and metropolises like Frankfurt-am-Main still exists this situation will continue, but if not the rivers will soon brake out of their man-made restrictions. The Rhine would return to its previous slow moving,winding courses and the basin would become again a marshy alluvial plain much as it was just 200 years ago.

1,000,000 years from now...

Our grandest monuments, except perhaps for the Pyramids or Mt. Rushmore, will have eroded into dust. All glass created up today will have dissolved and anyone watching the skies will see Betelgeuse go supernova for the last time. The world by this will be in the grip of another glacial period and Europe and our region will be again covered by advancing ice. The fertile hills, picturesque river valleys, and the remnant of our urban edifices (if still extant) will be ground to powder under the mile-thick sheet. Any land not covered by the ice sheet will be an arid, wind blown tundra, a Siberia moved westwards in other words.

100,000,000 years from now...

 Dr. Christopher Scotese's map of the global 150,000,000 years from now based on likely tectonic movements

Now we return to tectonics. The world now will look very different on the global scale. The Alpine orogeny will come to its destined acme 50,000,000 years before this, pushing Africa into the Eurasian plate. This will not only forever erase the Mediterranean basin but also create a new mountain chain to rival the Himalayas height and grandeur. This new combined continent will be further north than previously perhaps permanently placing the region in the sub-polar zone (if wobble of the Earth's orbit is even still the same by this point).

The Rhine may again exist but the Main might not. The movements of the glaciers previously could fill in its course. Meanwhile the Rhine will follow northward out of this new mountain range towards a new mouth and a new Arctic Ocean through a changed landscape. There in its middle course where great cities, old castles, and vineyards once stood will be a flattened plain, steppe lands covered in wild grass and devoid of trees. The land will still bear the scares of the glacial era in the form of the lakes and hills of fill material left behind after the ice melted. It will be a new world in its appearance,  a strange land likely devoid of humans and their works, but the processes shaping its geography that we have learned about this semester will still be the same.

References
Continents in Collision: Pangea Ultima - http://science.nasa.gov/science-news/science-at-nasa/2000/ast06oct_1/
Paleomap Project-Dr. Christopher Scotese - http://www.scotese.com/earth.htm
http://en.wikipedia.org/wiki/Geological_history_of_Europe
http://en.wikipedia.org/wiki/Timeline_of_glaciation
http://en.wikipedia.org/wiki/Rhine#Geologic_history
http://en.wikipedia.org/wiki/Alpine_orogeny
Timeline of the far future - http://www.bbc.com/future/story/20140105-timeline-of-the-far-future

Blog 2 - Mann und Erosion (Humans and Erosion)

Much like our own Mississippi, the Rhine remains a commercial highway as it has been for thousands of years. It also must be noted that this part of the river was straightened and dredged in the 19th century for the benefit of that traffic.

The natural evolution of  the Rhine-Main did not stop where we left off in the previous blog, of course, but continues to this day. As we learned in class, the landscape is constantly weathering and eroding, attempting to reach an equilibrium; humans have played a big part in this story for thousands of year, due to the invention of agriculture.

The ending of the Ice Age laid the groundwork for later human settlement. Although the rivers themselves were free of the glaciers, they were filled by the melting glaciers of the south and the Bavarian tablelands and loess, the silty, ground-up dust which the glaciers left in retreat, soon filled the alluvial plans of the subsided valleys and basins through which they flowed. Forests soon followed, filling the river-lands with thick, rich hardwood trees (of which the famous Schwarzwald or Black Forest is a latter day remnant). It is around three thousand years ago that people start to play their part; in clearing these old growth forests for farming, the early farmers unwittingly increased the Rhine's erosion and meandering, along with that sediment rapidly growing the size of the delta on which the modern Netherlands sits today. When the Romans arrived, they found a use for the marshy wetlands too, mining them for peat to be used in heating and salt production.

A monument to Johann Gottfried Tulla, the father of the modern Rhine

It was not until the Middle Ages that major attempts were first made to harness and control the rivers, beginning with Charlemagne's grand attempt to build a canal connecting the Rhine-Main with the Danube in the late 8th century (it is unknown if it was ever completed and only a short stretch remains today). During the 11-13th century in the high-point of the Medieval warm period, the new agricultural developments lead to the need to expand farmland and protect them; draining marshes, damning of minor tributaries, and embanking of major ones like the Main. Already in this period, people tried to stop the meandering and silting of the river via canals and Louis XIV even began to "move" the river in 1685, gaining France 1.5 kilometers of land by 1840. The major change to the nature of the river, however, was the work of Johann Tulla. A student of chemistry and mineralogy and proven field engineer, he was appointed director of the Oberdirektion des Wasser und Straßenbaues (Directorate of Water and Road Construction) in 1817 to plan and carry of the straightening and, I would say, taming of the Upper Rhine. The project was not completed until the 1870's, but it forever changed the river from a winding waterway with ox-bows and branching marshes (not at all dissimilar to the Mississippi) into a faster flowing, embanked one, controlled with dams. Yet, one can still find what the old Rhine looked like in the nature reserves around Mainz and Bingen and in an upcoming blog, we will look at the other efforts being made the preserve the natural aspects of the river system and the surrounding lands.

Sources:
Channel erosion and erosion monitoring along the Rhine River, B. Droge, H. Engel, E. Golz, 1992
http://en.wikipedia.org/wiki/Rhine
http://en.wikipedia.org/wiki/Upper_Rhine
http://en.wikipedia.org/wiki/Johann_Gottfried_Tulla

Blog 1 – Landschaft-Evolution (Landscape Evolution)

A lovely view of the Rhine-Main basin from the 10th hole of Rhineblick Golf Course (Wiesbaden, Germany)

The story of our region begins in the early Cenozoic era. One may recognize this era name for other grand events; the Cretaceous–Paleogene mass extinction and the accompanying rise in the fortunes of our mammalian ancestors, but it was also an era of continuing great geologic movements. As with the Indian plate’s movement northward, which we discussed in class, in this period the African plate was moving north against the Eurasian plate as well. This pressure threw up layers of metamorphosed sedimentary rock, which had previously for ages been ocean floor, in the form of the Pyrenees and the Alps. On the other side of these growing mountain ranges, the collision resulted in a substantial thinning of the lithosphere, isolated volcanism, and the formation of a rift system known as the European Cenozoic Rift System (ECRIS).

A digital elevation map of the Upper Rhine Graben and a side view of how it was formed

Like the more famous Great Rift Valley in Africa, the Rhine rift features a central linear depression (running on a north-south axis) through which the river runs; this is known as a graben (from the German word for ditch, coined by German geologists in the 19^th century when deciphering the geology of this region). This subsidence caused by the thinning of the lithosphere was also accentuated in some areas, the Vosges Mountains and the Black Forest for example, by uplifts on the rift flanks in excess of 2,500 meters. More recent glaciation throughout the Pleistocene add the finishing touch to the craving up of the landscape.

The ECRIS and the associated grabens and faults

The Rhine-Main is not only a junction of rivers, but also of faults; the Upper Rhine Graben meets the Lower Rhine Graben (which channels the river on via the Low Countries to the North Sea) and the inactive Hessian Grabens. This area has been the constant recipient of the worn down gravels and sands of the mountains and upper tributaries, creating a fertile plain in the basin 40-50 km in width.

Artist's impression of the Basel quake

The violent tectonic origins of the region have not only left their mark in geologic record, but human history as well. The Kaiserstuhl (Emperor's Chair) north of Freiburg is a cluster of old, now extinct volcanoes from the Miocene which in time became covered with a 10-40 meter layer of loess, clastic wind-blown silt. This has provided farmers with rich, well drained soil for intensive agriculture for hundreds of years; erosion being kept in check by the extensive use of terraces. Beneath the plain is one of the largest aquifers in Europe, holding an estimated 450,000 km3 of fresh water. 3 million people in Germany and France depend on this supply for three quarters of their drinking water. On the less positive side, seismic activity is not a thing of the past. During the early Middle Ages (c. 800 – 1000), chroniclers often made note of full earthquakes and tremors, which they reckoned was punishment for the sins of the people or monarch. The most destructive earthquake to occur in the region was the Basel earthquake in 1356, which flattened the city, drained lakes, and collapsed buildings up to 200 km away.

A view of the plain at the city of Mannheim (seen on the horizon)

As you can see, the evolution of the landscape has not just made pretty vistas for us to look upon; it continues to shape the life of people today even in regions of the world that you might never have considered "geologically active." We will dig more into this as we continue to explore the story of the Rhine-Main.

An Introduction

I am Elijah Wallace and I am returning to school after almost a decade's hiatus in order to complete my BA in History. From 2005 to 2013, I had the pleasure of serving in the United States Army and getting see many parts of our world that I would not have otherwise. One of these is the Rhine-Main region (in German, Frankfurt/Rhein-Main) of Germany; where I lived for four years of my service. Now one might say what's the big deal about a river valley in the middle of a relatively flat region of Europe. 

The Rhine forms the classical border of Germany and at this confluence of rivers lies one of historical heartlands of the nation. For example, Mainz and Trier were founded by Rome, on occasion themselves Imperial capitals, seats of the mighty medieval Prince-Archbishops, and sites of grand Gothic and Baroque architecture. Cities like Frankfurt am Main and Darmstadt even today help keep Germany's status high in the fields of economics and engineering. The area has seen millennia of bloodshed as various peoples have vied to control the farmland, commerce, and boundaries of the region (see France's never ending quest to make the Rhine her frontier). My intent in this blog is share the nature and beauty of this landscape as well as how that has effected the history of Germany and Europe as a whole.