Import proper UTF-8.

What's the point of Python defaulting to ASCII
when JSON is explicitly defined as a binary
format with a default character encoding of
UTF-8? 🙄

bin/human_exports_seis.py

@@ -25,8 +25,8 @@ def write_file (filename, payload):
 	print("Writing to", filename)
 	tmpname = filename.parent / (filename.name + ".tmp")
 	filename.parent.mkdir(parents=True, exist_ok=True)
-	with open(tmpname, "w") as fd:
-		json.dump(payload, fd, indent=4)
+	with open(tmpname, "w", encoding="utf8") as fd:
+		json.dump(payload, fd, indent=4, ensure_ascii=False)
 	os.rename(tmpname, filename)
 
 def seis_data (survey):