Fix typos and extend comments

include/aspect/mesh_deformation/fastscape.h

@@ -296,7 +296,7 @@ namespace aspect
 
  /**
  * Sediment rain in m/yr, added as a flat increase to the FastScape surface
- * every ASPECT timestep before running FastScape.
+ * in the marine domain every ASPECT timestep before running FastScape.
  */
  std::vector<double> sediment_rain_rates;
 
@@ -374,7 +374,7 @@ namespace aspect
  unsigned int left;
 
  /**
- * Paramters that set the fastscape boundaries periodic even though the ghost nodes are set 'fixed'
+ * Paramters that set the FastScape boundaries periodic even though the ghost nodes are set 'fixed'
  */
  bool topbottom_ghost_nodes_periodic;
  bool leftright_ghost_nodes_periodic;
@@ -408,7 +408,7 @@ namespace aspect
  */
 
  /**
- * @name Fastscape subaerial erosional parameters
+ * @name FastScape subaerial erosional parameters
  * @{
  */
 
@@ -418,7 +418,7 @@ namespace aspect
  double drainage_area_exponent_m;
 
  /**
- * Slope exponent for the steam power law. ($n$ variable in FastScape surface equation.)
+ * Slope exponent for the stream power law. ($n$ variable in FastScape surface equation.)
  */
  double slope_exponent_n;
 
@@ -460,7 +460,7 @@ namespace aspect
  double bedrock_transport_coefficient;
 
  /**
- * Bedrock transport coefficient for hillslope diffusion (m^2/yr). When set to -1 this is
+ * Sediment transport coefficient for hillslope diffusion (m^2/yr). When set to -1 this is
  * identical to the bedrock value.
  * (kd in FastScape surface equation applied to sediment).
  */
@@ -476,8 +476,10 @@ namespace aspect
 
  /**
  * Fastscape sea level (m), set relative to the ASPECT surface where
- * a sea level of zero will represent the maximum Y (2D) or Z (3D) extent
- * inside ASPECT.
+ * a sea level of zero will represent the initial maximum unperturbed
+ * Y (2D) or Z (3D) extent of the ASPECT domain. A negative value of
+ * the sea level means the sea level lies below the initial unperturbed
+ * top boundary of the domain. 
  */
  double sea_level;