CREATE TABLE table_48187 ("Outcome" CLOB, "Year" FLOAT, "Championship" CLOB, "Surface" CLOB, "Opponent" CLOB, "Score" CLOB)

What is Surface, when Championship is Australian Open?
SELECT "Surface" FROM table_48187 WHERE "Championship" = 'australian open'
SELECT "Surface" FROM "table_48187" WHERE "Championship" = 'australian open'