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_148578_1 (altitude__km_ VARCHAR, yield__approximate_ VARCHAR)
  ### Question:
  What was the altitude of the yield of 1.4 megatons?
  ### Answer:
  SELECT altitude__km_ FROM table_148578_1 WHERE yield__approximate_ = "1.4 megatons"