At initial time and at the singularization time:

<p>

<img src="images/surf2.jpg">

<p>
At five different times:
<p>

<img src="images/s1.jpg">
<img src="images/s2.jpg">
<img src="images/s3.jpg">
<img src="images/s4.jpg">
<img src="images/s5.jpg">