a) Excluding all natural fluctuations in climate i.e. unchanged rate of accumulation.
b) Assuming a Flat Earth i.e. horizontal subsurface.
c) Restricting ice flow to Vertical Compression and spreading Horizontal Bands.
The 1969 modelling of Vertical Compression resulted in the Horizontal Bands becoming exponentially thinner near the base of the ice sheet so that they could form the blade of the Holocene Hockey Stick chronology.
This ice flow model [in cross-section] is similar in concept to an Equal Area compression of a rectangle where a small reduction in height eventually results in a large horizontal expansion – just like rolling pastry.
However, the uniform nature of this Equal Area compression is disrupted if the ice sheet is placed in a basin – especially when the basin contains a sump.
In this situation the walls of the basin [and sump] will inhibit lateral deformation and prevent the exponential thinning of the lowermost layers.
Reviewing a 1975 radio-echo sounding image of the Greenland Ice Sheet near Camp Century reveals a similar regional situation where the upper ice dome appears to be flowing laterally over layers of dirty glacier ice.
Revisiting the data from the deep ice cores provides an opportunity to construct an indicative North-South cross-section of the ice sheet that roughly follows the arching “spine” of the Greenland Ice Sheet through 12 degrees of latitude.
The cross-section along the “spine” provides an indicative insight into the North-South profile of the dirty glacial ice [blue line] that is covered by the ice dome [white line].
The profile clearly indicates the ice layers within the ice sheet do not follow horizontal bands as assumed by the flow model used to create the Holocene Hockey Stick chronology.
Intriguingly, the depth of the volcanic benchmark “1259 Event” [red line] is shallower at the apex of the ice sheet [200 metres] than at Dye 3 in the South [369 metres] and at Camp Century in the North [263 metres].
This “shallow apex” pattern also appears in the depth of the dirty glacial bottom ice.
Plotting third-order polynomials from the data provides a more “rounded” view.
Projecting second-order polynomials forward [using only GISP2, NGRIP and Camp Century data] onto the rising bedrock further underlines the perspective that the ice layers within the main body of the ice sheet do not follow horizontal bands as assumed by the flow model that created the Holocene Hockey Stick.
The “rounded” cross-section through the Greenland Ice Sheet suggests that an evolutionary model for the ice dome should be based upon the growth of a hemisphere using Equal Volume expansion.
The Equal Volume expansion of a hemisphere indicates that the thinnest growth layers are at the apex [i.e. there is no Holocene Hockey Stick].
Subsequent vertical compression [squashing] of the Equal Volume Evolutionary ice sheet would result in the observed thinning of the apex layers and a counterbalancing thickening of layers towards the base of the ice sheet.
Clearly, the Flat Earth modellers need some time-out to rethink strategies and chronologies.
Perhaps a visit to an ice cream parlour might give them some inspiration.