Tuesday 21 November 2017

Natural Disasters and Family Misfortunes 9: Landslides

A recent news story out of Quebec, Canada, reminded me of another disaster that can affect people and communities. Earlier this month the bank along a portion of the Richelieu River collapsed leaving one home only a few feet away from falling into the chasm. Further erosion of the river bank continues, creeping further under the home’s foundation. The house has been condemned now as being unsafe and the owners have been forced to relocate. To make matters worse for this family, their insurance company will not pay to replace the house as this kind of loss falls into the natural disaster type of damage which is not covered by most policies.
 
Photo of 13 November 2017 collapse along Richelieu River (retrieved 16 Nov 2017 from The Weather Network website)
Situations such as occurred in Quebec happen often as lands along the margins of rivers or ocean and in mountainous areas give way to gravity, destroying everything in their path. Where people or property is present the damage can be more than just a natural erosion of land. Homes and businesses can be lost along with the lives of people caught unaware.

Throughout history there are many examples of landslides that ruined farms and communities. In some cases the slippages occurred over a longer period (weeks); in a few the events happened in just minutes. The latter inevitably were the most deadly as people in the path had little or no warning.

A 2014 landslide in Washington State took the lives of 43 people when a wall of mud, sand, water and trees virtually obliterated a residential community near the town of Oso.
 
An aerial image of the Oso landslide on 13 April 2014. Photo Credit: University of Illinois engineering professor Tim Stark (retrieved 17 November 2017 from phys.org website)
The area had received record-breaking rainfall in the preceding weeks, resulting in saturation of the slope. With the slide starting at a high elevation relative to the houses it built up a high degree of destructive energy against which little could withstand.

Along the southern coast of England, erosion has resulted in instability of the land. Major collapses have been records for the past five centuries. Normally they have begun with crack developing above the cliffs with subtle slipping of large blocks. Over periods of several days or weeks these blocks begin the slide toward the sea. Once moved, waves and currents begin their assault, taking away the material and leaving an undisturbed cliff wet hundreds of yards back from the original shoreline. And the process begins again.

One such event was chronicled in a special publication in 1840 (Coneybeare and Dawson’s memoir and Views of Landslips on the Coast of East Devon). In this book, the authors described the 1839 Bindon landslip in detail, and included several high quality illustrations. Landslips and erosion continue along the English coastline with many farms and towns in constant danger of being lost.

Like many other natural processes, landslides can result in devastating consequences. Often they accompany or are caused by earthquakes. Whether lives are actually lost – and there have been thousands over the centuries – livelihoods have certainly been impacted with loss of land and homes. In many instances, as with the recent case in Quebec, losses could not be replaced because either owners had no insurance or insurance policies did not pay out. In the past people may have been forced to leave areas where they had lived for decades, especially if their homes and businesses were gone.

A brief description of 26 catastrophic landslides of just the 20th century can be found here. A summary of landslides over the centuries can be seen here, The ten deadliest are listed here. The greatest loss of life occurred in Ningzia, China in December 1920 when a major earthquake triggered 675 landslides that resulted in massive destruction of property and claimed over 100,000 lives.


Genealogists might pay attention to the areas in which their ancestors lived to determine whether a natural event such as a landslide could have affected lives and livelihoods.