check file path

src/lib/src/main/java/gov/usgs/earthquake/nshmp/netcdf/Netcdf.java

@@ -38,6 +38,10 @@ public abstract class Netcdf<T> implements Comparable<Netcdf<T>> {
       throw new IllegalArgumentException("Path to Netcdf file [" + netcdfPath + "] does not exist");
     }
 
+    if (!netcdfPath.getFileName().toString().endsWith(".nc")) {
+      throw new IllegalArgumentException("NetCDF file not found (.nc) " + netcdfPath);
+    }
+
     var reader = getNetcdfData(netcdfPath);
     netcdfData = reader.netcdfData();
     netcdfShape = reader.netcdfShape();