What did Esperanza and Miguel do on the plateau?

In Las Uvas, shortly before her 14th birthday, Esperanza begs Miguel to drive with her to the foothills so that they can watch the sunrise. As she watches the sun come up, Esperanza can feel herself rising again. She soars over everything she has known for the past year, feeling revived and reborn like a phoenix emerging from the ashes. Once again, Miguel's hand brings her back down to earth. Together, they listen to the heartbeat of the earth and Esperanza feels at peace.

They followed the dirt road that headed east and parked when they could go no farther.
In the gray light, they could see a small footpath to a plateau.
When they got to the top, Esperanza looked out over the valley. The cool, almost-morning air filled her senses. Below, she could see the white roofs of the cabins in straight rows, the fields beginning to take form, and over the eastern mountains, a hopeful brightening. She bent over and touched the grass. It was cool but dry. She lay down on her stomach and patted the ground next to her. “Miguel, did you know that if you lie on the ground and stay very still, you can feel the earth’s heart beating?”
He looked at her skeptically.
She patted the ground again.
Then he lay down as she was, facing her.
“Will this happen soon, Esperanza?”
“Aguántate tantito y la fruta caerá en tu mano. Wait a little while and the fruit will fall into your hand.”
He smiled and nodded.
They were still.
She watched Miguel watching her.
And then she felt it. Beginning softly. A gentle thumping, repeating itself. Then stronger. She heard it, too. Shoomp. Shoomp. Shoomp. The earth’s heartbeat. Just like she had felt it that day with Papa.
Miguel smiled and she knew that he felt it, too.