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We use a mapped landslide inventory coupled with a 2‐m resolution vertical difference model covering an area of 6,875 km2 to accurately constrain landslide volume‐area relationships. We use the difference model to calculate the source volumes for landslides triggered by the MW 7.8 Kaikōura, New Zealand, earthquake of 14 November 2016. Of the 29,519 mapped landslides in the inventory, 28,394 are within the analysis area, and of these, we have calculated the volume of 17,256 source areas that are ≥90% free of debris. Of the 28,394 landslides, about 80% are classified as soil or rock avalanches and the remainder as mainly translational slides. Our results show that both the soil avalanches and the rock avalanches, ignoring their source geology, have area to volume power‐law scaling exponents (γ) of 0.921 to 1.060 and 1.040 to 1.138, respectively. These are lower than the γ values of 1.1–1.3 (for soil) and 1.3–1.6 (for rock) reported in the literature for undifferentiated landslide types. They are, however, similar to those γ values estimated from other coseismic landslide inventories. In contrast, for 50 selected rotational, translational (planar slide surfaces), or compound slides, where much of the debris remains in the source area, we found γ values range between 1.46 and 1.47, indicating that their slide surfaces were considerably deeper than those landslides classified as avalanches. This study, like previous studies on coseismic landslides, shows that soil and rock avalanches (disrupted landslides) are the dominant landslide type triggered by earthquakes and that they tend to be shallow. Key Points: We use a 2‐m resolution vertical difference model to estimate source volumes for 17,256 landslides with sources ≥90% free of debris triggered by the MW7.8 2016 Kaikōura EarthquakeThe model was derived by subtracting a tectonically adjusted pre‐EQ surface model from a post‐EQ model, covering an area of 6,875 km2Landslide trigger mechanism, type/failure mode, and source material are critical for accurate estimation of landslide volumes from source‐area geometries [ABSTRACT FROM AUTHOR]

Huimin Wu,1 Dorothy A Rhoades,2 Sixia Chen,3 Brent Brown1 1Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; 2General Internal Medicine, College of Medicine, and Stephenson Cancer Center, University of Oklahoma Health Sciences Center, OK, Oklahoma, USA; 3Biostatistics and Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USACorrespondence: Huimin WuPulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Oklahoma Health Sciences Center, 800 Stanton L Young Blvd, Suite 8400, Oklahoma City, OK, 73104, USATel +1 405-271-6173Fax +1 405-271-5892Email huimin-wu@ouhsc.eduPurpose: The prevalence of chronic obstructive pulmonary disease (COPD) and comorbidities (eg diabetes and obesity) among Native American (NA) population are higher than among the general US population. However, studies of COPD in NAs are scarce. Oklahoma has the largest NA population affiliated with federally recognized tribes in the country and is an ideal location for such research. A pilot study was designed to investigate the characteristics of NA patients with COPD exacerbations in a tertiary academic medical center.Patients and Methods: We conducted a retrospective exploratory study of NA adults with COPD exacerbation hospitalizations and/or emergency department visits at the University of Oklahoma Medical Center between July 2001 and June 2020. Medical records were reviewed to confirm COPD exacerbation and outcomes, including death, mechanical ventilation, intensive care unit (ICU) stay, home oxygen, and 30-day readmission. Additional collected data included socio-demographics, body mass index, diabetes, other COPD comorbidities and clinical variables.Results: Of 630 encounters reviewed, 159 met the inclusion criteria, representing 91 patients. Most patients were female (64%), obese or overweight (68%), and had diabetes (42%) or hypertension (71%). Mean age was 60 years old, but women were 5 years younger than men. Among the 76 patients with COPD hospitalizations, 31 patients (41%) had an intensive care unit (ICU) stay and 19 (25%) were intubated in their last hospitalization. Among 9 patients (10%) with 30-day readmissions, 8 were female. Medicare, Indian Health Service, Tribal health service, or Medicaid were the most frequently used payment sources. Sex, diabetes, and obesity were not associated with hospital length of stay, 30-day readmission or supplemental O2 use.Conclusion: Hospitalized NA COPD patients at this tertiary care center had multiple comorbidities. Many required ICU care and intubation. Larger studies of the risk and mitigating factors for COPD health outcomes in NA patients are needed.Keywords: COPD, Native American, comorbidities, hospitalization

The Canterbury, New Zealand, earthquake sequence, which began in September 2010, occurred in a region of low crustal deformation and previously low seismicity. Because, the ensuing seismicity in the region is likely to remain above previous levels for many years, a hybrid operational earthquake forecasting model for Canterbury was developed to inform decisions on building standards and urban planning for the rebuilding of Christchurch. The model estimates occurrence probabilities for magnitudes M ≥ 5.0 in the Canterbury region for each of the next 50 yr. It combines two short-term, two medium-term and four long-term forecasting models. The weight accorded to each individual model in the operational hybrid was determined by an expert elicitation process. A retrospective test of the operational hybrid model and of an earlier informally developed hybrid model in the whole New Zealand region has been carried out. The individual and hybrid models were installed in the New Zealand Earthquake Forecast Testing Centre and used to make retrospective annual forecasts of earthquakes with magnitude M > 4.95 from 1986 on, for time-lags up to 25 yr. All models underpredict the number of earthquakes due to an abnormally large number of earthquakes in the testing period since 2008 compared to those in the learning period. However, the operational hybrid model is more informative than any of the individual time-varying models for nearly all time-lags. Its information gain relative to a reference model of least information decreases as the time-lag increases to become zero at a time-lag of about 20 yr. An optimal hybrid model with the same mathematical form as the operational hybrid model was computed for each time-lag from the 26-yr test period. The time-varying component of the optimal hybrid is dominated by the medium-term models for time-lags up to 12 yr and has hardly any impact on the optimal hybrid model for greater time-lags. The optimal hybrid model is considerably more informative than the operational hybrid model at long time-lags, but less so when the period of the Canterbury earthquakes is excluded from the tests. The results highlight the value of including medium-term models and a range of long-term models in operational forecasting. Based on the tests carried out here, the operational hybrid model is expected to outperform most of the individual models in the next 25 yr. [ABSTRACT FROM AUTHOR]