September 23, 2021, 12:00-1:00 PT 

The EERI Northern California Regional Chapter and the EERI Learning from Earthquakes Program held a FREE webinar on the M8.2 earthquake that struck on July 28, 2021 (local date) offshore Alaska. The very strong quake was one of the largest to strike Alaska in recent history. It was located about 70 miles east southeast of Perryville, Alaska (about 500 miles southwest of Anchorage). The quake was a result of thrust faulting at a depth of 22 miles on the subduction zone between the Pacific plate and North American plate where the Pacific plate begins diving under Alaska. Fortunately, Alaska was mostly unscathed, thanks to the remote location and depth of the epicenter. Tsunami alerts were issued shortly after the earthquake and several coastal communities were evacuated. Only small tsunami waves measuring under a foot above tide level were observed initially, and tsunami alerts were called off under two hours after the quake. Final maximum wave amplitudes observed were between 1 and 2 feet above the tide, and the tsunami was detected down the U.S. West Coast as well as in Hawaii.

The Quick Quake Briefing featured two speakers from Alaska:

• Dr. Michael West, State Seismologist, Fairbanks, Alaska. He presented on the seismological mechanism of the earthquake, its relation to other recent earthquakes, and how it influences our thinking about future quakes.
• Dr. Summer Ohlendorf, Science Officer, NOAA/NWS/ National Tsunami Warning Center, Palmer, Alaska. She presented on the tsunami warning process following this quake, and the evolution of our understanding about the tsunami that was generated.

October 13, 2021, 11:00am–12:30 PM, Pacific Time

This EERI Learning from Earthquakes webinar provided a multi-disciplinary overview of preliminary observations from the M7.2 August 14, 2021 Haiti Earthquake. The earthquake caused widespread damage in the Nippes and Sud Departments, including the Port town of Les Cayes. This earthquake occurred 11 years after the deadly M7.0 2010 earthquake that hit closer to the capital city of Port-au-Prince. While the epicenter of the August earthquake was located more than 40 miles west of the densely populated capital area, casualties in the affected communities still numbered over 2,200 with more than 10,000 reported injured. The area also faced the additional challenge of Tropical Depression Grace, which made landfall two days after the earthquake, and whose strong winds and heavy rains hampered response and recovery efforts. The webinar covered the earthquake seismology, the humanitarian response, and scientific, engineering, social, and political impacts.

Speakers include:

• Maggie Ortiz-Millan, Senior Program Manager, EERI
• Sue Hough, Geophysicist, USGS
• Lindsey Davis, Earthquake Disaster Assistance Team (EDAT) Manager,
  USGS and USAID Earthquake Disaster Assistance Team
• Kate Allstadt, Research Geophysicist, USGS
• Shideh Dashti, Associate Professor of Geotechnical Engineering and Geomechanics, University of Colorado, Boulder; GEER
• Joanne Pérodin, MPH; Doctoral Candidate, Florida International University
• Gefthé Dévilmé, Field Officer, GeoHazards International
• Tracy Kijewski-Correa Linbeck Collegiate Chair and Associate Professor,
  University of Notre Dame; Director, StEER Network

Wednesday, October 20, 2021, 1:00–2:00 PM, Eastern Time

Cost: Free

The EERI New England Chapter held a free webinar on the evaluation of slope stability for Coal Combustion Residuals (CCR) impoundments. Such evaluation is becoming increasingly important as multiple failures involving undrained behavior of granular materials have recently occurred. Seismic loading is a load case where undrained behavior can be triggered that causes a rapid increase in mobilized shear stress or a rapid decrease in effective stress if contractive saturated materials are present. This rapid loading can trigger liquefaction within a CCR layer which would require considering the residual shear strength for the CCR material. The speakers summarized a study to improve understanding of the shear strength of CCR materials, discussing the approaches used to apply best applicable practices to make a reliable determination of peak and residual undrained shear strength of CCR materials, and provide recommendations on improving available methods to determine undrained shear strength of contractive materials.

Speakers:

• Dr. Seda Gokyer Erbis is a Project Engineer/Assistant Project Manager for Geocomp Corporation—Massachusetts Consulting Group.
• Ryan Lavorati is a Project Engineer at Geocomp Corporation—Massachusetts Consulting Group.

November 10, 2021
2:30-4:00 PM (Eastern), 11:30 AM-1:00 PM (Pacific)

This event was the third in a series of free public webinars featuring Dr. Craig Davis and building on the themes of his 2021 EERI Distinguished Lecture! Note: if you already registered for the series, you are pre-registered for this event, so all you need to do is save the date.

Historically, seismic design and building codes have focused primarily on ensuring safety in the event of an earthquake, with less attention to the state of structures and infrastructure systems in the aftermath. However, an increasing focus on resiliency in recent years has brought new attention to the concept of designing for functional recovery: a post-earthquake state in which capacity is sufficiently maintained or swiftly restored to support pre-earthquake functionality. As detailed in the January 2021 FEMA/NIST report “Recommended Options for Improving the Built Environment for Post-Earthquake Reoccupancy and Functional Recovery Time,” this means considering not only safety and recovery time for buildings, but ensuring recovery-based design, upgrade, and maintenance of a lifeline infrastructure systems as well. In this webinar, co-hosted by the EERI New England Regional Chapter and the University of Massachusetts at Amherst Student Chapter, EERI 2021 Distinguished Lecturer Craig Davis presented a short lecture on Lifeline Infrastructure System Functional Recovery and Operability, followed by a live panel with speakers from the US Army Corps of Engineers and the Massachusetts Department of Public Utilities. They spoke on the role, preparedness, and plans of their organizations to mitigate damage and restore service of critical lifeline systems after a disaster, and joined Dr. Davis for a Q&A session with the webinar audience.

Panelists:

• Dr. Craig Davis
  EERI 2021 Distinguished Lecturer
• Dr. Stephen Potts
  Geologist, U.S. Army Corps of Engineers
• Tirzah Shakespeare
  Public Utilities Engineer, Massachusetts Department of Public Utilities

About Dr. Craig Davis

In his three-decade-long career at the Los Angeles Department of Water and Power, Dr. Davis worked as the Departmental Chief Resilience Officer, Seismic Manager, and Geotechnical Engineering Manager, and developed a comprehensive L.A. Water System resilience program. He has served on professional committees, including the Building Seismic Safety Council, the National Earthquake Hazards Reduction Program Advisory Committee on Earthquake Hazards Reduction, and ASCE Infrastructure Resilience Division. Dr. Davis has published more than 150 technical papers and investigated numerous earthquakes.

Davis has been honored with the ASCE 2016 Le Val Lund Award for Practicing Lifeline Risk Reduction, the 2020 Charles Martin Duke Lifeline Earthquake Engineering Award, and the EERI Distinguished Lecture Award. The annual Distinguished Lecture Award is awarded to EERI members to recognize and encourage communication of outstanding professional contributions of major importance for earthquake hazard mitigation.

Friday, March 4th, 2022
12:00-1:00 PM (PST)

REGISTER HERE 

The EERI Younger Members Committee is hosting a webinar this Friday on earthquake liquefaction hazards. Soil liquefaction has led to significant damage and loss during earthquake events. Therefore, the evaluation of seismic liquefaction hazards – from the scale of individual sites and structures to the regional scale - is an essential part of seismic hazard resilience. This webinar will present three different studies on earthquake liquefaction that span from liquefaction site hazard evaluation and impact to structures, to regional scale hazard evaluation:

• Patrick Bassal (PhD Candidate, University of California, Davis) will first present a system-level study of liquefaction in interbedded soils during the Chi Chi Earthquake in Taiwan.
• The second presentation by Zach Bullock (Assistant Professor, University of British Columbia) will describe the development of probabilistic procedures for estimating the average settlement of shallow foundations above liquefiable soils.
• The final presentation by Hamed Tohidi (Adjunct Faculty, University of Memphis) will present the development of liquefaction hazard maps for the state of Tennessee.

There will be a 15-minute period following the presentations for audience questions and group discussion.