Question: the upper mantle below the earth's crust is known as the
[{'answer': 'asthenosphere', 'provenance': [{'wikipedia_id': '1079866', 'title': 'Mantle (geology)', 'start_paragraph_id': 6, 'start_character': 141, 'end_paragraph_id': 6, 'end_character': 154, 'bleu_score': 1.0, 'section': "Section::::Earth's mantle.:Structure.:Rheological structure.\n"}]}]