Extreme Weather week!

 We are discussing extreme weather events this week.

I'll be focusing on Heat waves this week. They occur more often than they used to in major cities across the United States, from an average of two heat waves per year during the 1960s to more than six per year during the 2010s. ... The average heat wave season across 50 major cities is 47 days longer than it was in the 1960s.

A few summers ago a mega heat wave left California and other Western states enduring the hottest summer on record. That wave killed more than 1 billion sea creatures in the Pacific Northwest!

These are measures that can help mitigate heat waves as we adapt to heat: (or aqui en Español)

• Provide community cooling centers, particularly in areas with low-income, elderly, and young populations
• Ensure proper functioning of energy and water systems
• Encourage citizens to check on their family, friends, and neighbors to ensure they have access to air conditioning
• Communicate heat warning information and appropriate responses to the public (e.g., encourage staying indoors, provide symptom reminders)
• Establish systems such as hotlines to alert public health officials about high-risk or distressed individuals
• Encourage energy conservation to reduce demand on electricity systems
• Implement load restrictions for older roads, bridges, and rail to reduce traffic on vulnerable transportation infrastructure

Sites like the Environmental America’s Extreme Weather Map (below) are interactive and help visualize the information of weather-related disasters  2010-2015. Every year, weather-related disasters injure or kill hundreds of Americans and cause billions of dollars in damage. Many of the risks posed by extreme weather will likely increase in a warming world. Scientists have already noted increases in extreme precipitation and heat waves as global warming raises temperatures and exacerbates weather extremes.

The WunderMap is a really useful site to see the severe weather occurrences updated in the States.

Any of the websites I used here are great places to keep yourselves informed so we can prepare for an extreme weather event.

Stay safe and informed!

Week: Volcanic Hazards

 There are about 169 volcanoes in the United States that scientists consider active (source). Most of these are located in Alaska, where eruptions occur virtually every year. Others are located throughout the West and in Hawaii (Ring of Fire anyone?). 

There are several ways we minimize the danger of volcanic activity (apart from the obvious of ‘getting out of the way’…(:

·         Forecasting (earthquakes as early warnings -although a Japanese volcano erupted without any previous seismicity (livescience article), land swelling before eruption, gas emissions, etc.)

·         Volcanic Alert Codes (USGS): the levels of alert and the aviation code levels commonly change at the same time (chart on right). A non-erupting volcano will have a green icon, and a red one indicates an imminent eruption (see USGS Alert Codes).

Today the US hazards map (below) shows 5 volcanoes as to be above normal background (elevated unrest); map below:

Kilauea and Great Sitkin, Alert Level= WATCH. Aviation Color Code = Orange.

Spurr, Atka, Ahyi Seamount, Alert Level= ADVISORY. Aviation Color Code = Yellow

If you want to know more about volcanoes and how we monitor them, there is a MOOC from the University of Iceland you might want to enroll into. A short video explanation here. 

Week 3: Earthquakes

  We are exploring earthquakes and what countries do to prevent/mitigate the hazard. If I want to know something about earthquakes in a place, the first websites I go to are: the USGS Real Time Earthquakes Website or the IRIS monitoring website.

Regarding where quakes are located in the US, the new seismicity map below from USGS shows the (obvious, in red) ring of fire portion on the West coast but also a central area in the middle of the plate. I’d like to talk a bit more about this non-obvious one. This area, called the New Madrid Zone was shaken by a M8(!) in 1811. The reason for the activity is a very old intraplate rift placed below the area (see image from http://showme.net).

The San Andreas Fault System is responsible for most of California natural quakes...Each year the southern California area has about 10,000 earthquakes.!! The latest swarm of quakes in the Salton Sea has been featured in the news often. Earthquakes up to magnitude 4.6 under the Salton Sea are raising concern that a larger quake could be unleashed on the San Andreas fault. The southernmost section of the fault has not ruptured since about 1680.

So, what can we do about it?; apart from the obvious need for education, I want to focus on the USGS ShakeAlert system, developed for the West coast using some of the existing systems. Today, the technology exists to detect earthquakes, so quickly, that an alert can reach some areas before strong shaking arrives. The purpose of an EEW (Earthquake Early Warning) system is to identify and characterize an earthquake a few seconds after it begins, calculate the likely intensity of ground shaking that will result, and deliver warnings to people and infrastructure in harm’s way. Studies of earthquake early warning methods in California have shown that the warning time would range from a few seconds to a few tens of seconds, depending on the distance to the epicenter of the earthquake. 

There is an Earthquake Tracker all Californians can download to keep informed: try My Shake App.

A few seconds of warning could make all the difference (enough to stop transit/elevators and to drop, cover, hold on).This year's International ShakeOut Day is October 17, when millions of people worldwide will participate in earthquake drills at work, school, or home!

Being aware of the risk and know what to do when the shaking starts is very important. We know that earthquakes cannot be predicted (I recommend Dr. Jones’ book called the big ones’ if you want more information about that)

Week 2: Tectonics

 This week we are exploring Plate Tectonics and how important it is to know the location of the plate boundaries, and how it is closely related to some natural hazards, like volcanoes or earthquakes.

In the US, the NOAA map below shows how the Easter part of the States is a passive margin, and the Western side of the country is a very active one, with the Pacific Plate, Cocos, Juan de Fuca plates connecting to the North American plate. Not a surprise we are on the ‘Ring of Fire’, where a lot of the volcanic and seismic activity happens!

Closer to home, the transform plate boundary called SAF (San Andreas Fault) is responsible for most of the shaking. These plates (North American and Pacific) are slowly moving past one another at a couple of inches a year; about the same rate that your fingernails grow! Our amazing SAF is also a right strike slip fault. 

Of course, there are a few exceptions, like the activity of Hawaii within the Pacific plate (hot spot) or the New Madrid area (ancient rift) within the North American Plate, both not at plate boundaries, but that will be another post another time...

We might not know when events like volcanic eruptions or big earthquakes will happen (a lot of these happen underwater...), but if you know your Tectonics, you definitely know WHERE they (mostly) do!