Safe Human Settlement Policy Initiative

Safe Human Settlement Policy Initiative

Wednesday, November 29, 2017

Imaging Tool to Map Hazards

A recent article by the Washington (State) Geological Survey demonstrates the uses of Lidar (light detection and ranging) technology to map geological hazards. The article explains the process and illustrates its use with fascinating case studies involving hazards common to the Pacific Northwest:  Landslides and Volcanoes.  The article goes on to describe applications of the technology in locating fault lines, predicting tsunami inundation zones, and tracking the courses of rivers over time to predict flooding impact.  The process can also yield incredible images of sub-surface geology.

Clearly the benefits for applying the technology to hazard identification and mitigation are immeasurable.  Hopefully, it will also become a useful tool in educating and convincing policy makers and the general public to address the hazards in a real way.  Being able to target action and resources to more specific geographical locations will be a significant benefit to endangered communities.

Lidar image of the glaciers on Mt. Rainier. (From the Article)

The online, interactive article is well worth your time to read.

Tuesday, November 14, 2017

What Difference Does A Week Make?

Last Sunday, there was a 7.3 earthquake reported in Iran, near the Iraqi border.  Just 8 hours later, Costa Rica experienced a 6.5 quake.  These were on the heels of 5 major earthquakes (>6.0) reported over the last week, plus dozens of moderate quakes (>4.0) that hit hotspots like the Pacific Rim.  News reports called the Iranian quake the deadliest of the year, adding that “at least 452 people were killed and thousands injured… and was felt as far away as Turkey and Pakistan.” 

Scientists are divided about an increase in the frequency of earthquakes and statistics show ebbs and spikes are cyclical over time.  Other natural events—particularly weather events—do seem to be increasing, if not in frequency, at least in strength.   

Interestingly, there those scientists who think the two may be related, at least on some level.  They’ve identified statistical (indirect) relationships between the two.  Others have demonstrated that a phenomenon known as “slow earthquakes” can be triggered by major atmospheric disturbances like hurricanes and typhoons.  (Wikipedia defines a slow earthquake as “a discontinuous, earthquake-like event that releases energy over a period of hours to months, rather than the seconds to minutes characteristic of a typical earthquake.") That sounds like an interesting topic for another time.

The message here is that, whether they are increasing or we’re simply experiencing an anecdotal spike in natural disasters, they will continue to come. Nobody is predicting a reduction in the future.  Thus building resilience into our cities and adapting our communities to survive these events should remain a top priority.