text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE table_name_4 (diameter__km_ INTEGER, name VARCHAR, year_named VARCHAR)
  ### Question:
  Which Diameter (km) has a Name of alma-merghen planitia, and a Year named smaller than 1997?
  ### Answer:
  SELECT MAX(diameter__km_) FROM table_name_4 WHERE name = "alma-merghen planitia" AND year_named < 1997