Wald is involved in the research, development, and operations of real-time information systems at the USGS National Earthquake Information Center.[7] He has developed and manages products such asShakeMap and the community-science systemDid You Feel It?. He is also responsible for developing other systems for post-earthquake response and pre-earthquake mitigation, such as ShakeCast andPAGER.[8] He has also contributed to the USGS Ground Failure product.[9][10] As well as management of these systems, Wald's research also focuses on characterization of rupture processes from complex earthquakes, analysis of ground motions and site effects, and modeling earthquake-induced events.[11]
On top of his publications, Wald is also known for hosting events and giving lectures about geophysics topics, including a "Provost’s Lecture" atStony Brook University[12] and an EERI Younger Members Committee webinar.[13]
Wald then began working at the USGS in Pasadena in 1993 as aNational Research Council Post-Doctoral Fellow and stayed on there as a researcher. He and his wife, Lisa Wald,[15] who also works for the USGS,[16] later transferred to the Golden, Colorado USGS office to work at the NEIC.[14]
Wald was a developer ofPAGER, a post-earthquake analytic system. He is also the primary developer and distributor ofShakeMap.[17] Other products of note developed or managed by Wald include:
ForDid You Feel It? (DYFI),[18] Wald leveraged the work of Lori Dengler and Jim Dewey following theNorthridge earthquake. Their large volume of macroseismic phone surveys motivated them to create a "community decimal intensity" by assigning numerical values to individual questionnaire responses that they could calibrate against theModified Mercalli Intensity scale, the macroseismic intensity scale in use in the U.S. The numerical assignment of intensities from questionnaires lent itself naturally to automating the entire process of data collection, intensity assignment, and publishing via the internet, which today creates community-sourced maps of perceived intensity after an earthquake.[19]
DYFI has been operating for over two decades (1999–present)[20] in the U.S. and over 18 years globally. The survey has collected over 6 million individual DYFI intensity reports during that period. DYFI allows for high rates and quantities of macroseismic data collection. High-quality MMI maps can be made almost immediately with complete coverage at a higher resolution than in the past.[21]
In and around 2000, via contacts with theCaltech ERA, Wald began interacting with many utility and lifeline operators. A common query was, "Given a ShakeMap, how can I tell what the level of shaking was at each of my facilities?” Working initially with Phil Naecker, an IT and infrastructure consultant, and with support from Loren Turner of the California Department of Transportation (Caltrans), David's team prototyped ShakeCast—short for ShakeMap Broadcast. ShakeCast was developed as a post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap to compare ground shaking intensity measures against a user’s facilities.[22]
ShakeCast is now a fully automated software system for delivering specific ShakeMap products to critical users and triggering established post-earthquake response protocols. ShakeCast generates potential damage assessments and inspection priority notifications, maps, and web-based products for critical users, emergency managers, and anyone specified on a need-to-know basis.[23][24]
As perScopus, Wald has over 11 thousand citations and anh-index of 50,[33] whereas according toGoogle Scholar, he boasts over 21 thousand citations and a 67h-index.[34]Semantic Scholar lists him between the two, with over 15 thousand citations and a 57h.[35]
