"close to vertical" is correct and usable in written English.
You can use it when you need to indicate how close a surface or object is to the vertical position. For example, "The rock wall was close to vertical, making it difficult to climb."
Jimmy spent his time out in the weed-blistered lot behind the house, kicking a football as close to vertical as he could, over and over again, then slanting off to retrieve it before it could hit the ground.
While in air, the robot uses the drive wheels to maintain its body angle close to vertical.
end{aligned} (16) (J_u) can be interpreted as the field-aligned current (Birkeland current), since the field lines are very close to vertical at polar latitudes.
The plunges of the maximum and intermediate compressive stress axes are close to horizontal, and the plunge of the minimum compressive stress axes is close to vertical (Fig. 11).
Although the orientation of the stress tensors derived from the first and second data subsets is different, the transtensional stress regime (σ1 close to vertical, σ2 and σ3 close to horizontal) and the stress magnitude ratio close to R = 0.8 are common features (Figs. 14, 15, 16).
The distribution of the P- and T-axes of the focal mechanism of the aftershocks in the cluster indicates that most of the aftershocks have a predominantly normal faulting mechanism where the P-axis trend is close to vertical and the T-axis trend is close to horizontal (Fig. 13(d)).
The inversion results show that the maximum and intermediate principal stress axes are closer to horizontal and that the minimum compressive stress axis is closer to vertical, indicating a transpressive tectonic stress regime (Table 1) in the western part of the Gulf of Izmit, which well fits the structural models (Gökaşan et al., 2001; Cormier et al., 2006).
On the other hand, when the peptides were spread on a mixture of water and methanol, the orientation of helical peptides was closer to vertical than that on water and the monolayers were transferred repeatedly on gold to form multilayers with a vertical orientation.
The amount of adjustment became smaller as the observer reported that he/she saw the disk falling closer to vertical.
Average saccade size decreased to 7.1 ± 1.2 degrees and the direction moved closer to vertical, 17 ± 8 degrees to the left of the vertical meridian.
These are increasingly covered with new jerry-built houses that cling precariously to steep slopes so close to the vertical as to be almost cliffs.
