STEER REPORTS

MArch 3, 2020

In the early morning hours of March 3, 2020, a strong tornado struck the City of Nashville and the surrounding metropolitan region with estimated maximum wind speeds of 165 mph. The tornado passed through Nashville and continued east for 53 miles, impacting the communities of Donelson, Mt. Juliet and Lebanon before lifting. The same storm system then produced a second tornado that struck Cookeville, TN with estimated wind speeds of 175 mph. The Nashville tornado was the third tornado that passed through the Five Points area of Nashville. Damage was reported across a diverse cross-section of buildings spanning a number of communities: Camden, Germantown/North Nashville, East Nashville/Five Points, Donelson, Mt. Juliet, Lebanon and Cookeville. Exposure of an urban metro area to this series of tornadoes resulted in significant impacts to power infrastructure and building performance ranging from loss of roof cover and broken windows to complete destruction. Affected typologies and building classes include single and multi-family wood framed homes, commercial construction (ranging from big box stores down to smaller restaurants/retail shops), airport and industrial buildings, and a number of schools. More gravely, these nocturnal tornadoes claimed two dozen lives and injured hundreds more. Given the loss of life and property in this event and the fact that the Nashville tornado sequence impacted an urban area with diverse building classes and typologies, this event offers an opportunity to advance our knowledge of structural resistance to strong winds, particularly given that new construction was among the inventory significantly damaged. This project encompasses the products of StEER's response to this event: Preliminary Virtual Reconnaissance Report (PVRR), Early Access Reconnaissance Report (EARR) and Curated Dataset.

October 19, 2020

Structural damage from Hurricane Delta was minimal based on public reports and direct observations by the FAST members. As peak wind gusts from Delta were well below design levels, this outcome was not unexpected. Roof cover damage was commonly observed across Delta’s wind field, although preliminary observations by FAST did not indicate a well-defined damage gradient. The lack of a noticeable damage gradient may be a by-product of the joint hurricane impacts of Laura and Delta. As illustrated in Figure 4.1, the juxtaposition of Laura and Delta’s wind fields created a large swath of 90-100 mph wind speeds within which damage patterns were more uniform. Economic impacts of roof cover loss in a hurricane are often severe and disproportionate to the level of structural damage observed. A few examples of Hurricane Delta causing additional damage beyond Laura were observed by the FAST members, but these instances did not appear widespread. However, many areas southeast of Lake Charles were not documented by StEER following Hurricane Laura, so it was difficult to separate damage by storm in these areas. Moreover, as field observations affirmed little to no progress in recovery of damaged properties, the dislodged tarps and additional water penetration from rainfall and flooding in Delta will only further delay the recovery and compound losses. The streetview data collected by Delta FASTs encompasses many of the same areas imaged in Laura, providing a valuable longitudinal dataset to explore recovery rates, debris evidence of interior losses in Laura, and potential for compounding losses from these sequential hurricanes. The societal impacts of Hurricane Delta are likely severe, but will require additional research to document. For example, there are likely to be mental health impacts of two hurricane landfalls within weeks of each other, and additional health consequences resulting from widespread evacuation and disruption of testing and contact tracing during the COVID-19 pandemic. Critical supply chains like oil and gas production were also disrupted at the highest levels since Hurricane Katrina. Such questions are outside the scope of StEER, but worthy of investigation by other EER researchers.

November 8, 2020

Hurricane Zeta began as a tropical disturbance 300 miles southeast of the Yucatan Peninsula, where it made its first landfall on the island of Cozumel as a Category 1 hurricane, before moving onto the peninsula near Tulum on the evening of 26 October 2020. Weaking overland, as the storm moved back into the Gulf of Mexico, it restrengthened, reaching a peak intensity with a sustained wind speed of 110 mph as it made landfall as a Category 2 hurricane on the Louisiana coast near Cocodrie, a fishing village in Terrebonne Parish, at 4:00 PM CDT on 28 October 2020. It was a fast-moving storm, with a 24 mph translating speed, and it continued to accelerate after landfall, tracking across Mississippi, Alabama, Georgia, North Carolina and Virginia, where it became post-tropical as it merged with a cold front.

November 14, 2020

This event briefing is intended to: (1) summarize the impacts of Hurricane/Tropical Storm Eta across Central and North America with emphasis on structural losses, (2) document the hazard intensity associated with the storm, and (3) identify any lessons learned from this event. While StEER did reach out to contacts in Central America in attempts to collect field observations, this outreach was unsuccessful. Thus all content herein is derived from public reports from news services, mission agencies and social media.

November 14, 2020

The objectives of this PVRR are: 1) to provide details of the 30 October Mw 7.0 Aegean Sea earthquake, 2) to describe local codes and building practices, 3) to compare the recorded ground shaking with the values used for design, 4) to summarize the preliminary reports of damage to buildings and other infrastructure, including the disruption to the community in terms of fatalities, downtime, and economic losses, and 5) to highlight key lessons learned, with recommendations to inform the continued study of this event by the natural hazards engineering community. As the product of mostly virtual reconnaissance, the PVRR is not based upon detailed field investigations by StEER, though some field observations from members and collaborators in the region are included.