# A New Ground-Motion Prediction Model for Shallow Crustal Earthquakes in Turkiye
## 4 Results and Discussion
Another important criterion for reducing standard deviation is the preference for distance metrics that are closest to the fault rupture (such as \(R_{JB}\), \(R_{rup}\)) instead of epicentral (\(R_{epi}\)) or hypocentral (\(R_{hyp}\)) distances for large-magnitude events (\(M_{W}\) > 5.5). The proposed GMPMs emphasize ground-motion amplitudes with independent predictor variables consisting of magnitude, faulting style, distance, and site scaling. The results of the study are summarized below:  
* The between-event residuals show no significant trends, though records from the Van earthquake (\(M_{W}\) 7.1) fall below the median. This discrepancy is likely due to the interaction between the variable stress drop and the kappa term. The weak ground motions from the Van earthquake are inconsistent with finite-fault distance metrics. * A strong correlation was found between one component of the standard deviation (between-event standard deviations) and magnitude. As the magnitude increases, \(\tau\) decreases, and this pattern is independent of the period. * By incorporating a heteroscedastic model for between-event variability, the GMPMs address the magnitude-dependent nature of ground-motion variability, particularly for large events (\(M_{W}\) > 6.5). * The inclusion of non-linear site amplification terms ensures accurate predictions for high-amplitude ground motions, particularly for soft soil conditions (low \(V_{530}\) values). * The models are validated for events ranging from \(M_{W}\) 4.0 to 7.8 and source-to-site distances up to 350 km. These limits ensure their applicability for a wide range of engineering and seismic hazard scenarios. Here are the suggested limits for the predictor variables applied in our GMPMs:
* Magnitude (\(M_{W}\)) range: 4.0-7.8,
* Events: mainshocks and aftershocks,
* Distance (\(R_{JB}\)) range: 0-350 km,
* Event depth: shallower than 35 km,
* Style of faulting (SoF): \(SS\), \(NS\), and \(RS\),
* Range of applicable site conditions (\(V_{530}\)): 131-1862 m/s,* GMIMs (RotD50): PSA at 5% damping for 36 periods in the 0.01-10 s range, PGA and PGV. Our GMPEs were developed for application in tectonically active shallow crustal regions and should not be used for other tectonic regimes unless their applicability can be verified. Conceptualization, U.C. ; data curation, U.C. ; methodology, U.C. and A.I. ; software, U.C. and A.I. ; validation, U.C. and A.I. ; resources, U.C. ; writing--original draft, U.C. ; writing--review & editing, U.C., A.I. and F.S. ; visualization, U.C. ; supervision, F.S. All authors have read and agreed to the published version of the manuscript. No funding was received to support this research or manuscript. Not applicable. The strong-motion dataset used in this article are published in the following databases: The Turkish strong-motions are obtained from the web site (TADAS, [[https://tadas.afad.gov.tr/login](https://tadas.afad.gov.tr/login)]([https://tadas.afad.gov.tr/login](https://tadas.afad.gov.tr/login)) last accessed August 2024) operated and maintained by the Earthquake Department of the Turkish Disaster and Emergency Management Authority, Engineering Strong-Motion (ESM, [[https://www.orfeus-eu.org/data/strong](https://www.orfeus-eu.org/data/strong)]([https://www.orfeus-eu.org/data/strong](https://www.orfeus-eu.org/data/strong)), last accessed, 15 April 2023), An Updated Strong-Motion Database of Turkish (SMD-TR) (DesignSafe-CI. [[https://doi.org/10.17603/ds2-f21x-s1](https://doi.org/10.17603/ds2-f21x-s1)]([https://doi.org/10.17603/ds2-f21x-s1](https://doi.org/10.17603/ds2-f21x-s1)) 89 last accessed 12 August 2024). This publication is a part of doctoral dissertation by the first author in the Academic Program of Geophysical Engineering, Faculty of Engineering, Kocaeli University. We also thank anonymous reviewers for their valuable comments. The strong-motion data used in this article provided by Disaster and Emergency Management Presidency (AFAD).