diff --git a/src/ProfileProcessing.jl b/src/ProfileProcessing.jl
index c4795b774..ddc9e2cec 100644
--- a/src/ProfileProcessing.jl
+++ b/src/ProfileProcessing.jl
@@ -35,7 +35,7 @@ mutable struct ProfileData
     ScreenshotData::Union{Nothing, NamedTuple}
 
     function ProfileData(; kwargs...) # this constructor allows to define only certain fields and leave the others blank
-        K = new(true, nothing, nothing, nothing, nothing, nothing, nothing)
+        K = new(true, nothing, nothing, nothing, nothing, nothing, nothing, nothing, nothing)
         for (key, value) in kwargs
             # make sure that start and end point are given as tuples of Float64
             if key == Symbol("start_lonlat")
@@ -617,14 +617,12 @@ function extract_ProfileData(ProfileCoordFile::String, ProfileNumber::Int64, Dat
     # load all Data
     VolData, SurfData, PointData, ScreenshotData, TopoData = load_GMG(Datasets_all)
 
-    # merge VolData:
-    VolData_combined = combine_vol_data(VolData)
-
-    # project data onto profile:
+    # project data onto profile (volume datasets are processed individually, without merging them first):
     extract_ProfileData!(
-        profile, VolData_combined, SurfData, PointData;
+        profile, VolData, SurfData, PointData;
         DimsVolCross = DimsVolCross, DimsSurfCross = DimsSurfCross,
-        Depth_extent = DepthVol, section_width = WidthPointProfile
+        Depth_extent = DepthVol, section_width = WidthPointProfile,
+        ScreenshotData = ScreenshotData, TopoData = TopoData
     )
 
     return profile
diff --git a/test/test_ProfileProcessing.jl b/test/test_ProfileProcessing.jl
index 040198d8a..7c21e2fc0 100644
--- a/test/test_ProfileProcessing.jl
+++ b/test/test_ProfileProcessing.jl
@@ -53,6 +53,9 @@ VolData_combined2 = combine_vol_data(Data.Volume, dims = (50, 51, 52))
 VolData_combined3 = combine_vol_data(Data.Volume, lon = (1, 22), lat = (40, 52), dims = (50, 51, 52))
 @test isnan(VolData_combined3.fields.Hua2017_Vp[1000])
 
+# ProfileData has a TopoData field, which is empty by default
+@test isnothing(ProfileData(depth = -10).TopoData)
+
 # Define horizontal & vertical profiles
 prof1 = ProfileData(start_lonlat = (5, 45), end_lonlat = (15, 49))
 prof2 = ProfileData(depth = -100)